161 (number)

From Wikipedia, the free encyclopedia
← 160 161 162 →
160 161 162 163 164 165 166 167 168 169
List of numbersIntegers
0 100 200 300 400 500 600 700 800 900
Cardinalone hundred sixty-one
Ordinal161st
(one hundred sixty-first)
Factorization7 × 23
Divisors1, 7, 23, 161
Greek numeralΡΞΑ´
Roman numeralCLXI
Binary101000012
Ternary122223
Octal2418
Duodecimal11512
HexadecimalA116

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 the military[]

In music[]

In transportation[]

  • MTA Maryland commuter bus 161
  • Seattle Metro bus route 161
  • New Jersey Bus Route 161
  • London Bus route 161

In other fields[]

161 is also:

  • The year AD 161 or 161 BC
  • is a year in the Islamic calendar that corresponds to 777778 CE
  • The atomic number of an element temporarily called Unhexunium
  • 161 Athor is an M-type Main belt asteroid
  • E.161 is an ITU-T assigns letters to the 12-key telephone keypad
  • Fiorina Fury 161 is a foundry facility and penal colony from the film Alien 3
  • 161 is used by Anti Fascist Action as a code for AFA (A=1, F=6, by order of the alphabet), sometimes used in 161>88[3] (88 is code for Heil Hitler among neo-nazis, as H=8)

See also[]

External links[]

References[]

  1. ^ "Sloane's A002412 : Hexagonal pyramidal numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
  2. ^ "A002113 - Oeis".
  3. ^ "161>88". Czech Republic: Antifascist Action. 2012. Archived from the original (Documentary) on 3 January 2018. Retrieved 2 January 2018.
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