Deficient number

A natural number is called deficient if their proper divisors sum (the sum of all divisors excluding the number itself ) is smaller than the number itself is the divisor sum, however, equal to the number, it is called a perfect number, it is larger, then one speaks of an abundant number.

Examples:

If the divisor sum only one less than the number, then one speaks of a slightly deficient number. All powers of the number 2 are slightly deficient:

( from phosphorus Zahlomat 2004)

The listing of the first deficient numbers can be found in ( sequence A005100 in OEIS ).

  • Integer amount
225210
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