yetkin sayı

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Турецкий язык - Английский Язык
perfect number
A number that is the sum of all of its divisors except itself

The factors of 28 are 1, 2, 4, 7, 14 and 28, and 1 + 2 + 4 + 7 + 14 = 28, so 28 is a perfect number.

A positive integer that is equal to the sum of its positive integral factors, including 1 but excluding itself