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 120

  • 120 is the smallest 3-perfect number — the sum of its divisors is equal to itself times 3
  • 120 is the largest integer n for which the number of primes less than or equal to n equals n/4
  • 120 is the smallest number to appear 6 times in Pascal's triangle
  • The internal angles of a regular hexagon are all 120 degrees
  • 120 is the number of 1-piece positions at checkers
  • 120 is the smallest triangular number whose digit permutations yield at least two other triangular numbers (120 yields 21 and 210)
  • 120 is the smallest number that can be represented as a product of consecutive integers in more than one way: 120 = 2*3*4*5 = 4*5*6
  • 120 is the smallest even triangular number followed by a composite number

Rare Properties of 120

Factorial
Tetrahedral (Pyramidal)

Common Properties of 120

Abundant
Composite
Even
Evil
Practical
Triangular
Untouchable