168 (one hundred [and] sixty-eight) is the natural number following 167 and preceding 169.

← 167 168 169 →
Cardinalone hundred sixty-eight
Ordinal168th
(one hundred sixty-eighth)
Factorization23 × 3 × 7
Divisors1, 2, 3, 4, 6, 7, 8, 12, 14, 21, 24, 28, 42, 56, 84, 168
Greek numeralΡΞΗ´
Roman numeralCLXVIII
Binary101010002
Ternary200203
Senary4406
Octal2508
Duodecimal12012
HexadecimalA816

In mathematics edit

168 is an even number, a composite number, an abundant number, and an idoneal number.[1]

There are 168 primes less than 1000. 168 is the product of the first two perfect numbers.

168 is the order of the group PSL(2,7), the second smallest nonabelian simple group.

From Hurwitz's automorphisms theorem, 168 is the maximum possible number of automorphisms of a genus 3 Riemann surface, this maximum being achieved by the Klein quartic, whose symmetry group is PSL(2,7).[2] The Fano plane has 168 symmetries.

168 is the largest known n such that 2n does not contain all decimal digits.[3]

168 is the fourth Dedekind number.

In astronomy edit

In the military edit

In movies edit

In transportation edit

In other fields edit

168 is also:

 
There are 168 pips on a double-six set of dominoes.

See also edit

References edit

  1. ^ "Sloane's A000926 : Euler's "numerus idoneus" (or "numeri idonei", or idoneal, or suitable, or convenient numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-28.
  2. ^ "week214". math.ucr.edu. Retrieved 9 April 2023.
  3. ^ "Sloane's A130696: Numbers k such that 2^k does not contain all ten decimal digits". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-12-19.
  4. ^ "$1 Prosperity Forever 168 Note - US Mint". Retrieved 9 April 2023.

External links edit