13 (number)

← 12 13 14 →
← 10 11 12 13 14 15 16 17 18 19 → List of numbers — Integers ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	thirteen
Ordinal	13th (thirteenth)
Numeral system	tredecimal
Factorization	prime
Prime	6th
Divisors	1, 13
Roman numeral	XIII
Binary	11012
Ternary	1113
Quaternary	314
Quinary	235
Senary	216
Octal	158
Duodecimal	1112
Hexadecimal	D16
Vigesimal	D20
Base 36	D36

13 (thirteen /θɜːrˈtiːn/) is the natural number following 12 and preceding 14.

In spoken English, the numbers 13 and 30 are often confused. When carefully pronounced, they differ in which syllable is stressed: 13 ⁱ/θɜːrˈtiːn/ vs. 30 /ˈθɜːrti/. However, in dates such as 1300 ("thirteen hundred") or when contrasting numbers in the teens, such as 13, 14, 15, the stress shifts to the first syllable: 13 /ˈθɜːrtiːn/. In a 24-hour clock, the thirteenth hour is in conventional language called one or one o'clock.

Strikingly similar folkloric aspects of the number 13 have been noted in various cultures around the world: one theory is that this is due to the cultures employing lunar-solar calendars (there are approximately 12.41 lunations per solar year, and hence 12 "true months" plus a smaller, and often portentous, thirteenth month). This can be witnessed, for example, in the "Twelve Days of Christmas" of Western European tradition.^[1]

In mathematics

The number 13 is:

• the sixth prime number.
• the smallest emirp (a prime that is a different prime when reversed).^[2]
• one of only 3 known Wilson primes.^[3]
• a Fibonacci number.
• a happy number^[4]
• the third centered square number.^[5]
• equal to the sum of the squares of the digits of its own square in bases 4 and 83.

Since 5² + 12² = 13², (5, 12, 13) forms a Pythagorean triple.

There are 13 Archimedean solids, and a standard torus can be sliced into 13 pieces with just 3 plane cuts.^[2] There are also 13 different ways for the three fastest horses in a horse race to finish, allowing for ties, a fact that can be expressed mathematically by 13 being the third ordered Bell number.^[6]

List of basic calculations

Multiplication	1	2	3	4	5	6	7	8	9	10		11	12	13	14	15	16	17	18	19	20		21	22	23	24	25		50	100	1000
13 × x	13	26	39	52	65	78	91	104	117	130		143	156	169	182	195	208	221	234	247	260		273	286	299	312	325		650	1300	13000

Exponentiation	1	2	3	4	5	6	7	8	9	10		11	12	13
13x	13	169	2197	28561	371293	4826809	62748517	815730721	10604499373	137858491849		1792160394037	23298085122481	302875106592253
x13	1	8192	1594323	67108864	1220703125	13060694016	96889010407	549755813888	2541865828329	10000000000000		34522712143931	106993205379072	302875106592253

In languages

Grammar

• In all Germanic languages (such as English and German), 13 is the first compound number (in German dreizehn); the numbers 11 and 12 have their own names (in German elf and zwölf).
• The Romance languages use different systems: In Italian, 11 is the first compound number (undici), as in Romanian (unsprezece), while in Spanish and Portuguese, the numbers up to and including 15 (Spanish quince, Portuguese quinze), and in French up to and including 16 (seize) have their own names.
• This is also the case in most Slavic languages, Hindi-Urdu and other South Asian languages.

Spelling

In Germany, according to an old tradition, 13 (dreizehn) as the first compound number was the first number written in digits; the numbers 0 (null) through 12 (zwölf) were spelt out. The Duden (the German standard dictionary) now calls this tradition (which was actually never written down as an official rule) outdated and no longer valid, but many writers still follow it.

For the English language, different systems are used: Sometimes it is recommended to spell out numbers up to and including nine or ten or twelve, like formerly in German, or even ninety-nine or one hundred. Another system spells out all numbers written in one or two words (sixteen, twenty-seven, fifteen thousand, but 372 or 15,001 ).

In religion

Roman Catholicism

The apparitions of the Virgin of Fátima in 1917 were claimed to occur on the 13th day of six consecutive months.^[7]

In Catholic devotional practice, the number thirteen is also associated with Saint Anthony of Padua, since his feast day falls on June 13. A traditional devotion called the Thirteen Tuesdays of St. Anthony^[8] involves praying to the saint every Tuesday over a period of thirteen weeks. Another devotion, St. Anthony's Chaplet, consists of thirteen decades of three beads each.^[9]

Sikhism

According to famous Sakhi (Evidence) or story of Guru Nanak Dev Ji, when he was an accountant at a town of Sultanpur Lodhi, he was distributing groceries to people. When he gave groceries to the 13th person, he stopped because in Gurmukhi and Hindi the word 13 is called Terah, which means yours. And Guru Nanak Dev Ji kept saying, "Yours, yours, yours..." remembering God. People reported to the emperor that Guru Nanak Dev Ji was giving out free food to the people. When treasures were checked, there was more money than before.

The Vaisakhi, which commemorates the creation of "Khalsa" or pure Sikh was celebrated on April 13 for many years.

Judaism

• In Judaism, 13 signifies the age at which a boy matures and becomes a Bar Mitzvah, i.e., a full member of the Jewish faith (counts as a member of Minyan).
• The number of principles of Jewish faith according to Maimonides.
• According to Rabbinic commentary on the Torah, God has 13 Attributes of Mercy.

Zoroastrianism

The number 13 had been considered sinister and wicked in ancient Iranian (Persian) civilization and Zoroastrianism. Since beginning of the Nourooz tradition, the 13th day of each new Iranian year is called Sizdah Be-dar, and this tradition is still alive among Iranian people both within Iran and abroad. Since Sizdah Be-dar is the 13th day of the year, it is considered a day when evil's power might cause difficulties for people. Therefore, people leave urban areas for one day and camp in the countryside. Even in the current post-1979 Revolution era, and despite the wishes of Islamic government, this tradition continues to be practiced by the majority of the population throughout Iran.

Shia

In Shia 13 signifies the 13th day of the month of Rajab (Lunar calendar), which is the birth of Imam Ali. 13 also is a total of 1 Prophet and 12 Imams in the Shia school of thought.

Wicca

In Wicca, most covens have 13 members, although sometimes there can be fewer.

Other

• In Mesoamerican divination, 13 is the number of important cycles of fortune/misfortune (see Trecena).
• The Thirteen Classics is considered to be a part of the Chinese classics.

Lucky and unlucky

Unlucky 13

The number 13 is considered an unlucky number in some countries.^[10] The end of the Mayan calendar's 13th Baktun was superstitiously feared as a harbinger of the apocalyptic 2012 phenomenon.^[11] Fear of the number 13 has a specifically recognized phobia, Triskaidekaphobia, a word coined in 1911. The superstitious sufferers of triskaidekaphobia try to avoid bad luck by keeping away from anything numbered or labelled thirteen. As a result, companies and manufacturers use another way of numbering or labelling to avoid the number, with hotels and tall buildings being conspicuous examples (thirteenth floor).^[12] It's also considered unlucky to have thirteen guests at a table. Friday the 13th has been considered an unlucky day. ^[10]

There are a number of theories as to why the number thirteen became associated with bad luck, but none of them have been accepted as likely.^[10]

• The Last Supper: At Jesus Christ's last supper, there were thirteen people around the table, counting Christ and the twelve apostles. Some believe this is unlucky because one of those thirteen, Judas Iscariot, was the betrayer of Jesus Christ.
• Knights Templar: On Friday 13 October 1307, King Philip IV of France ordered the arrest of the Knights Templar,^[10] and most of the knights were tortured and killed.
• Full moons: A year with 13 full moons instead of 12 posed problems for the monks in charge of the calendars. "This was considered a very unfortunate circumstance, especially by the monks who had charge of the calendar of thirteen months for that year, and it upset the regular arrangement of church festivals. For this reason thirteen came to be considered an unlucky number."^[13] However, a typical century has about 37 years that have 13 full moons, compared to 63 years with 12 full moons, and typically every third or fourth year has 13 full moons.^[14]
• A repressed lunar cult: In ancient cultures, the number 13 represented femininity, because it corresponded to the number of lunar (menstrual) cycles in a year (13 x 28 = 364 days). The theory is that, as the solar calendar triumphed over the lunar, the number thirteen became anathema.^[10][15]

Lucky 13

In many countries, such as Italy, 13 is considered a lucky number.^[16] The expression fare tredici ("to do 13") means hit the jackpot. 17 is considered an unlucky number instead.

Music

American born Horror-Punk singer and musician Joseph Poole (Murderdolls) uses the name Wednesday 13 as his stage name, taking "Wednesday" from the girl Wednesday from the Addams Family and 13 from Friday the 13th.

American country-pop singer-songwriter Taylor Swift was born on December 13. She considers 13 her lucky number due to lucky events happening to her when the number appears (her first album going gold in 13 weeks, being seated at awards shows in the 13th seat, row or section). She also wears the number written on her hand at her concerts so she has it with her everywhere she goes.

The heavy metal band, Megadeth, released their 13th studio album entitled TH1RT3EN on November 1, 2011. It consists of 13 tracks including the final song "13".

Famous American country singer and songwriter Johnny Cash first released his song called "Number Thirteen".

There are 13 notes, by inclusive counting, in a full chromatic musical octave.

Track No. 12 on American heavy metal band Danzig's album 6:66 Satan's Child is called "Thirteen".

The band Big Star wrote a song called 13.

The band Teenage Fanclub named their album Thirteen after Big Star's song. The band were heavily influenced by Big Star.

American alternative rock band, Pixies recorded "Number 13 Baby" for their Doolittle LP. The lyrics to the song include the line: "Standing in her chinos shirt pulled off clean, gotta tattooed tit say number 13"

English alternative rock band Blur's sixth studio album, entitled 13 was released in 1999.

The British heavy metal pioneers Black Sabbath's latest studio album is entitled 13. It was released on 11 June 2013.

The gothic metal band Type O Negative has a song titled "Thir13teen", which is the debut track of their album Life Is Killing Me.

13 is an album from the American death metal band Six Feet Under.

Other

Colgate University also considers 13 a lucky number. They were founded in 1819 by 13 men with 13 dollars, 13 prayers and 13 articles.^[17] (To this day, members of the Colgate community consider the number 13 a good omen.) In fact, the campus address is 13 Oak Drive in Hamilton, New York, and the male a cappella group is called the Colgate 13.

In the Mayan Tzolk'in calendar, trecenas mark cycles of 13-day periods. The pyramids are also set up in 9 steps divided into 7 days and 6 nights, 13 days total.

In the standard 52-card deck of playing cards there are four suits, each of 13 ranks.

In a tarot card deck, XIII is the card of Death, usually picturing the Pale horse with its rider.

A 24-hour clock uses the number 13 in the form of 13:00-13:59, to represent the fourteenth hour of its 24-hour cycle.

A baker's dozen, devil's dozen, long dozen, or long measure is 13, one more than a standard dozen.

Age 13

• In Judaism, 13 signifies the age at which a boy matures and becomes a Bar Mitzvah, i.e., a full member of the Jewish faith (is qualified to be counted as a member of Minyan).
• This is the first year a person is considered a teenager in Germanic languages, due to the suffix form beginning at this point (11 & 12 are nonstandard).
• This is also the age in the US, a person can watch, rent, or buy a PG-13 film without parental guidance.

History

• The United States of America was created from thirteen British colonies and as such, the number thirteen is a commonly recurring motif in American heraldry. For example, there are thirteen stars on the Great Seal of the United States and there are thirteen stripes on the American flag.
  • The first flag of the United States bore thirteen stripes, alternating red and white, and thirteen white stars in the blue union. The thirteen stripes represented the Thirteen Colonies from which the United States was created, and the thirteen stars represented the number of states in the new nation. When two new states were added to the Union in 1795, the flag bore fifteen stars and fifteen stripes. With the addition of five new states in 1818, the number of stripes was re-set and permanently fixed at thirteen.
  • The Great Seal of the United States bears many images of the number thirteen, representing the Thirteen Colonies from which the United States was created. On the Seal’s observe, the overhead glory bears thirteen stars. The chest shield in front of the spread eagle bears thirteen stripes (seven white and six red). In the eagle’s right talon, it holds the Olive Branch of Peace, bearing thirteen olives and thirteen olive leaves. In the eagle’s left talon, it holds the Weapons of War, consisting of thirteen arrows. In the eagle’s mouth, it holds a scroll bearing the national motto “E Pluribus Unum” (which, by coincidence, consists of thirteen letters). On the Seal’s reverse, the unfinished pyramid consists of thirteen levels.
• Apollo 13 was a NASA Moon mission famous for being a "successful failure" in 1970.

In sports

In rugby league:

• Each side has 13 players on the field at any given time.
• The jersey number 13 is worn by the starting loose forward or lock forward in most competitions. An exception is in the European Super League, which uses static squad numbering.

The jersey number 13 has been retired by several North American sports teams, usually in honor of past playing greats:

• In Major League Baseball:
  • The Cincinnati Reds, for Dave Concepción.
• In the NBA:
  • The Charlotte Hornets, for Bobby Phills, who died in a 2000 auto accident while playing for the team. From 2002, when the original Hornets moved to New Orleans (eventually becoming the New Orleans Pelicans), to 2014, when the franchise formerly known as the Charlotte Bobcats reclaimed both the Hornets name and the history of the 1988–2002 Hornets, the number had been honored by the New Orleans franchise.
  • The Golden State Warriors, Los Angeles Lakers, and Philadelphia 76ers, all for Hall of Famer Wilt Chamberlain.
  • The Portland Trail Blazers, for Dave Twardzik.
  • The San Antonio Spurs, for James Silas.
  • The Phoenix Suns, for Steve Nash.
• In the NFL:
  • The Miami Dolphins, for Hall of Famer Dan Marino.
  • The New York Jets, for Hall of Famer Don Maynard.
• The Toronto Maple Leafs of the NHL have a policy of not retiring numbers unless the number's bearer either died or suffered a career-ending incident while a member of the team. Other players whose numbers would otherwise be retired instead have their numbers enshrined by the team as "Honoured Numbers", which remain in circulation for future players. The number 13 is currently honoured for Hall of Famer Mats Sundin.

In Formula 1, the number 13 was used by Pastor Maldonado in 2015, after having been unused for 36 (see below) years.

In triathlon, the number 13 is not used. As such, the numbering goes 11, 12, 14, 15 under the current numbering system. The number was not used in Formula One from 1977 to 2013.

In U.S. college athletics, schools that are members of NCAA Division I are allowed to provide athletic scholarships to a maximum of 13 men's basketball players in a given season.

In rugby union, the jersey number 13 is worn by one of the two starting centres, usually the outside centre but sometimes the inside centre.

The number 13 is the most-commonly registered jersey number in modern roller derby.^[18]

In boxing, after the death of boxer Duk Koo Kim following a world championship fight with World Boxing Association Lightweight champion of the world Ray Mancini (which, coincidentally, took place on November 13, 1982) the World Boxing Council determined that boxers were more likely to suffer fatal injury from round 13 to round 15, therefore soon after boxing fights were universally limited to a maximum of 12 rounds only.^[19]

In TV and films

• 13TH, a 2016 documentary
• 13 (musical), a 2007 musical
• 13 (film), an English-language remake of the 2005 French film 13 Tzameti.
• Thirteen (film), a 2003 American film
• Number 13 (film), an uncompleted Hitchcock 1922 film
• 13 Tzameti, a 2005 French film ("Tzameti" means "13" in Georgian)
• 13 Ghosts is a 1960 horror film.
  • Thirteen Ghosts a 2001 remake.
• Thirteen is the nickname of Dr. Remy Hadley on the American medical drama House played by Olivia Wilde.
• 13 Assassins is a 2010 film by Japanese director Takashi Miike
• The Thirteen is a 1936 Soviet war film by Mikhail Romm
• The 13th Warrior is a 1999 historical fiction action film starring Antonio Banderas
• District 13 is a 2004 French film (with David Belle)
• Apollo 13 is a 1995 American film.
• In the various incarnations of the television series Battlestar Galactica, the twelve human colonial worlds are destroyed by the mechanical Cylons. The few human survivors then make an interstellar exodus in search of the lost thirteenth colony on a planet called – Earth.
• Warehouse 13 is a television show about the 13th warehouse in the line of warehouses that store supernatural artifacts.
• Friday the 13th is a horror film series involving a mass murderer named Jason Voorhees.
• Friday the 13th: The Series is a syndicated American-Canadian horror television series, that originally ran from 1987 to 1990.
• The 13 Ghosts of Scooby-Doo: Seventh incarnation of the Hanna-Barbera Scooby-Doo cartoon franchise, first run 1985-1986.
• The Thirteenth Floor is a 1999 sci-fi film.
• 13B/Yaavarum Nalam is a 2009 Hindi/Tamil Horror movie starring R Madhavan

References

Wikimedia Commons has media related to 13 (number).