Number Gossip

(Enter a number and I'll tell you everything you wanted to know about it but were afraid to ask.)

Unique Properties of 20

  • 20 is the maximum number of moves needed to solve the Rubik's cube
  • In a game of chess both players have 20 first moves from which to choose
  • 20 is the smallest number that cannot be either prefixed or followed by one digit to form a prime
  • 20 is the largest number of set cards without a set
  • 20 is the smallest number n such that 6n-1 and 6n+1 are composites

Rare Properties of 20

Pronic (Heteromecic)
Tetrahedral (Pyramidal)

Common Properties of 20