120 (one hundred twenty in American English; one hundred and twenty in British English) is the natural number following 119 and preceding 121. 120 was known as "the great hundred", especially prior to the year 1700, from the Teutonic Hundert which equalled 120. The number 100, now known commonly as "one hundred" was then known as "the small hundred". It is also known as 'twelvety' according to the number naming system invented by J. R. R. Tolkien (c.f. eleventy).

In mathematics

It is the eighth hexagonal number and the fifteenth triangular number, as well as the sum of the first eight triangular numbers, making it also a tetrahedral number. 120 is divisible by the first 5 triangular numbers and the first 4 tetrahedral numbers.

120 is the first multiply perfect number of order three (a 3-perfect number, triperfect). The sum of its factors (including one and itself) sum to 360; exactly three times 120. Note that perfect numbers are order two (2-perfect) by the same definition.

120 is divisible by the number of primes below it, 30 in this case. However there is no integer which has 120 as the sum of its proper divisors, making 120 an untouchable number.

The sum of Euler's totient function φ(x) over the first nineteen integers is 120.

120 figures in Fermat's modified Diophantine problem as the largest known integer of the sequence 1, 3, 8, 120. Fermat wanted to find another positive integer that multiplied with any of the other numbers in the sequence yields a number that is one less than a square. Euler also searched for this number, but failed to find it, but did find a fractional number that meets the other conditions, 777480 / 2879².

The internal angles of a regular hexagon (one where all sides and all angles are equal) are all 120 degrees.

120 is a Harshad number in base 10.

In religion

• The cubits of the height of the Temple building (II Chronicles 3:4)
• The age at which Moses died (Deut. 34:7). "Ad me'ah v'esrim shanah" (עד מאה ועשרים שנה) is a common Hebrew blessing for longevity
• The number of Men of the Great Assembly who canonized the Books of the Tanakh and formulated the Jewish prayers
• The number of talents of gold Queen Sheba gave to King Solomon in tribute (I Kings 10:10)
• The number of princes King Darius set over his kingdom (Daniel 6:2)
• The weight in shekels of the gold spoons offered by each tribe of Israel (Num. 7:86).

In the military

• USNS Mission San Carlos (T-AO-120) was a United States Navy Mission Buenaventura-class fleet oiler during World War II
• USS Jaguar (IX-120) was a United States Navy Armadillo-class tanker during World War II
• USS Mindoro (CVE-120) was a United States Navy vessel which launched June 27, 1945
• USS Radford (DD-120) was a United States Navy Wickes class destroyer during World War I
• USS S-15 (SS-120) was a United States Navy S-class submarine which launched March 8, 1920
• USS Spokane (CL-120) was a United States Navy Atlanta-class light cruiser which launched September 22, 1945
• USS Sway (AM-120) was a United States Navy Auk-class minesweeper during World War I
• USS Zaniah (AK-120) was a United States Navy Basilan-class cargo ship during World War II

In TV

• The TV series "Sister, Sister" ran on ABC and the WB Network from 1994 to 1999 for 120 episodes
• The TV series "The Fugitive" ran on ABC from 1963 to 1967 for 120 episodes
• The TV series “Batman” ran on ABC from 1966 to 1968 for 120 episodes
• The TV series “The Muppet Show” ran in syndication from 1976 to 1981 for 120 episodes

In other fields

• 120 (2008 film) - Turkish movie, based on a real story in World War I
• 120 AH is a year in the Islamic calendar that corresponds to 737 – 738 CE
• 120 Minutes is a television show dedicated to alternative music on MTV and MTV2
• Central African Republic ranks #120 in world population
• Embraer EMB 120 Brasilia is a twin-turboprop commuter airliner
• London Buses route 120 is a Transport for London contracted bus route in London
• Mercedes-Benz W120/121 Ponton cars produced between 1953 and 1962
• STS-120 is a Space Shuttle Discovery mission to the International Space Station launched October 23, 2007
• 120 is a 2007 movie starring Kim Piazza
• 120 is the typical number of credits needed to graduate with a Bachelor's Degree in the United States
• 2 hours is 120 minutes
• A medium film format introduced by Kodak in 1901 and still in use today
• An old alternative meaning of the word "Hundred", and the meaning of the Teutonic word "Hundert"
• Channel 120 on Sirius Satellite Radio is ESPN Radio
• In astrology, when two planets in a person's chart are 120 degrees apart from each other, this is called a trine. This is supposed to bring good luck in the person's life
• In Super Mario 64 for the N64 120 is the maximum number of power stars you can get, and the max number of shine sprites in Super Mario Sunshine
• The atomic number of Unbinilium, an element yet to be discovered
• The medical telephone number in China
• The 120th Kentucky Derby was won by Go for Gin on May 7, 1994
• The 120th Westminster Kennel Club Dog Show was won by Ch. Clussexx Country Sunrise, a Clumber Spaniel in February, 1996
• The 120th annual Tournament of Roses Parade is scheduled for January 1, 2009
• The book 120 Days of Sodom written by French author Marquis de Sade in 1785
• The year AD 120 or 120 BC

See also

• List of highways numbered 120
• United Nations Security Council Resolution 120

References

• Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 135