Deficient numbers

A kind of number

About Deficient numbers

A deficient number is a positive integer for which the sum of its proper divisors is less than the number itself. All prime numbers are deficient; so are powers of primes and many composites.

Key features

  • Primes and prime powers are deficient.
  • There are infinitely many deficient numbers.

Examples:

1, 2, 3, 4, 5, 7, 8

Further reading