161 (number)

161 1, 7, 23, 161 161 (one hundred [and] sixty-one) is the natural number following 160 and preceding 162. In mathematics 161 is the sum of five consecutive prime numbers: 23, 29, 31, 37, and 41. 161 is a hexagonal pyramidal number.https://oeis.org/A002412 Sloane's A002412 : Hexagonal pyramidal numbers The On-Line Encyclopedia of Integer Sequences OEIS Foundation 2016-05-28 161 is a semiprime. Since its prime factors 7 and 23 are both Gaussian primes, 161 is a Blum integer. 161 is a palindromic number.https://oeis.org/A002113 A002113 - Oeis 161 72 is a commonly used rational approximation of the square root of 5 and is the closest fraction with denominator <300 to that number. In other fields 161 as a code for Anti-Fascist Action (A=1, F=6, by order of the alphabet), sometimes used in 161>88161>88 http://film.antifa.cz/?page_id=37 Antifascist Action 2 January 2018 Czech Republic Documentary 2012 3 January 2018 https://web.archive.org/web/20180103072614/http://film.antifa.cz/?page_id=37 dead (88 being code for Heil Hitler among neo-nazis, as H=8) External links Number Facts and Trivia: 161 The Number 161 VirtueScience: 161 https://web.archive.org/web/20210124001925/https://www.virtuescience.com/161.html 2021-01-24 References 1 Category:Integers