180 (number)
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180 (one hundred [and] eighty) is the natural number following 179 and preceding 181.
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| Cardinal | One hundred [and] eighty | ||
| Ordinal | 180th | ||
| Factorization |  |
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| Divisors | 1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 30, 36, 45, 60, 90, 180 | ||
| Roman numeral | CLXXX | ||
| Binary | 10110100 | ||
| Duodecimal | 130 | ||
| Hexadecimal | B4 | ||
| Vigesimal | 90 | ||
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[edit] In mathematics
180:-) is an abundant number, with its proper divisors summing up to 366.[1][2] 180 is also a highly composite number, a positive integer with more divisors than any smaller positive integer. One of the consequences of 180 having so many divisors is that it is a practical number, meaning that any positive number smaller than 180 that is not a divisor of 180 can be expressed as the sum of some of 180's divisors.
180 is the sum of two square numbers: 122 + 62. It can be expressed as either the sum of six consecutive primes: 19 + 23 + 29 + 31 + 37 + 41, or the sum of eight consecutive primes: 11 + 13 + 17 + 19 + 23 + 29 + 31 + 37. 180 is an Ulam number, which can be expressed as a sum of earlier terms in the Ulam sequence only as 177 + 3.
Half a circle has 180 degrees.[3]
Summing Euler's totient function φ(x) over the first + 24 integers gives 180.
180 is a Harshad number in base 10, and in binary it is a digitally balanced number, since its binary representation has the same number of zeros as ones (10110100).
[edit] In sports
- A "180" is a trick in extreme sports where a rider rotates half a turn while airborne and lands.
- The maximum possible score in one turn at darts (three triple 20s).
- In archery the gent's clout shooting distance is 180 yards.[4]
[edit] In other fields
180 is also:
- The year AD 180 or 180 BC
- 180 is an astrological aspect considered to be negative in influence.[citation needed]
- Scores on the Law School Admission Test (LSAT) are converted to a scaled score from 120 - 180.
- Lithol Rubine BK, food dye classification #E180
- John Wayne, an American film actor, starred in 180 films.
- In the Final Destination series, number 180 is the number of Death.
[edit] See also
- List of highways numbered 180
- United Nations Security Council Resolution 180
- United States Supreme Court cases, Volume 180
- Pennsylvania House of Representatives, District 180
- United States v. Gouveia, 467 U.S. 180 (1984)
[edit] References
- ^ "Positive Integers: 180". http://www.positiveintegers.org/180.
- ^ a b "The Number 180". VirtueScience.com. http://www.virtuescience.com/180.html.
- ^ Wells, D. (1987). The Penguin Dictionary of Curious and Interesting Numbers. London: Penguin Group. p. 142. ISBN 0-14-026149-4.
- ^ GNAS (2008). "Grand National Archery Society Rules of Shooting April 2008". http://www.sportfocus.com/reguser/dynabizinfo/download.cfm?number=2908.
[edit] External links
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Wikimedia Commons has media related to: 180 (number) |
- "180". The Number Dictionary. http://www.numdic.com/180.
- G. L. Honaker, Jr. "Prime curiosities: 180". UTM. http://primes.utm.edu/curios/page.php/180.html.
