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.[1]
- 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[2]
- 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>88[3] (88 being code for Heil Hitler among neo-nazis, as H=8)
External links
- Number Facts and Trivia: 161
- The Number 161
- VirtueScience: 161 Archived 2021-01-24 at the Wayback Machine
References
- ^ "Sloane's A002412 : Hexagonal pyramidal numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
- ^ "A002113 - Oeis".
- ^ "161>88". Czech Republic: Antifascist Action. 2012. Archived from the original (Documentary) on 3 January 2018. Retrieved 2 January 2018.
