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 89

  • 89 is the smallest number for which the positive sum of all odd primes less than or equal to it is a square
  • 89 is the smallest prime that is a concatenation of pq and qp where p and q are prime
  • 89 is the smallest prime whose digits are composites
  • 89 is the only two-digit number that is the sum of its first digit and its second digit squared

Rare Properties of 89

Fibonacci

Common Properties of 89

Deficient
Evil
Odd
Prime
Square-free