161 (number)
Natural number
From Wikipedia, the free encyclopedia
161 (one hundred [and] sixty-one) is the natural number following 160 and preceding 162.
Cardinalone hundred sixty-one
Ordinal161st
(one hundred sixty-first)
(one hundred sixty-first)
Factorization7 × 23
Divisors1, 7, 23, 161
| ||||
|---|---|---|---|---|
| Cardinal | one hundred sixty-one | |||
| Ordinal | 161st (one hundred sixty-first) | |||
| Factorization | 7 × 23 | |||
| Divisors | 1, 7, 23, 161 | |||
| Greek numeral | ΡΞΑ´ | |||
| Roman numeral | CLXI, clxi | |||
| Binary | 101000012 | |||
| Ternary | 122223 | |||
| Senary | 4256 | |||
| Octal | 2418 | |||
| Duodecimal | 11512 | |||
| Hexadecimal | A116 | |||
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
Wikimedia Commons has media related to 161 (number).
- Number Facts and Trivia: 161
- The Number 161
- VirtueScience: 161 Archived 2021-01-24 at the Wayback Machine