180 (number)

the number other uses 180 (disambiguation) 180 1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 30, 36, 45, 60, 90, 180 180 (one hundred [and] eighty) is the natural number following 179 and preceding 181. In mathematics 180 is an abundant number, with its proper divisors summing up to 366.Positive Integers: 180 http://www.positiveintegers.org/180The Number 180 http://www.virtuescience.com/180.html VirtueScience.com 2009-05-29 2021-01-23 https://web.archive.org/web/20210123232210/https://www.virtuescience.com/180.html dead 180 is also the 11th highly composite number,A002182 - OEIS https://oeis.org/A002182 2024-11-28 oeis.org a positive integer with 18 divisors, more than any smaller positive integer.A002182 Highly composite numbers 2016-05-30 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 a Harshad number and a refactorable number.https://oeis.org/A033950 Refactorable numbers 2016-04-18 On-Line Encyclopedia of Integer Sequences The OEIS Foundation 2016-04-18 180 is the sum of two square numbers: 122 + 62. It can be expressed as either the sum of six consecutive prime numbers: 19 + 23 + 29 + 31 + 37 + 41, or the sum of eight consecutive prime numbers: 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.https://oeis.org/A002858 Ulam numbers 2016-04-18 On-Line Encyclopedia of Integer Sequences The OEIS Foundation 2016-04-18 180 is a 61-gonal number, while 61 is the 18th prime number. Half a circle has 180 degrees,D. Wells The Penguin Dictionary of Curious and Interesting Numbers Penguin Group 1987 London 142 0-14-026149-4 and thus a U-turn is also referred to as a 180. Summing Euler's totient function φ(x) over the first + 24 integers gives 180. In binary it is a digitally balanced number, since its binary representation has the same number of zeros as ones (10110100). A triangle has three interior angles that collectively total 180 degrees. In general, the interior angles of an -sided polygon add to degrees. References External links 180 http://www.numdic.com/180 The Number Dictionary Prime curiosities: 180 http://primes.utm.edu/curios/page.php/180.html G. L. Honaker, Jr UTM 1 Category:Integers