abundant number

A natural number whose proper divisors sum to more than the number. For example, the proper divisors of 12 are 1, 2, 3, 4, and 6, and these add up to 16. Since 16 > 12, 12 is an abundant number. A number whose proper divisors sum to less than the number is called deficient, and one whose proper divisors sum to exactly itself is called perfect.