divisor function

English

Noun

divisor function (plural divisor functions)

1. (mathematics) A function yielding the sum of the divisors of an integer. It is denoted by the Greek letter σ (sigma).

   The value of the divisor function for 20 is 1 + 2 + 4 + 5 + 10 + 20 = 42, denoted as σ(20) = 42.