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 1021

  • 1021 is the smallest four-digit prime whose sum of digits is equal to its length
  • 1021 is the smallest four-digit prime which yield a prime after removing two outermost digits
  • 1021 is the smallest prime number in which the sum of the external digits equals the sum of the internal digits

Common Properties of 1021

Deficient
Lucky
Odd
Odious
Prime
Square-free
Twin