Abundant number checker

Check if a number is abundant. A number is abundant if the sum of its proper divisors is greater than itself.

Number

Abundant numbers

A number is abundant if σ(n) − n > n, i.e. proper divisors sum to more than n. The first abundant numbers: 12, 18, 20, 24, 30, 36, 40, 42, 48, 54, 56, 60, 66, 70, 72, 78, 80, 84, 88, 90...

Example

12: proper divisors = 1+2+3+4+6 = 16 > 12 → abundant. The "abundance" is 16 − 12 = 4.