Define a functionS:⁺⁺as follows.

For each positive integern,S(n) = the sum of the positive divisors ofn.

Find the following. (For each answer, enter an exact number.)

Define a function S : Z+ - Z+ as follows. For each positive integer n, S(n) = the sum of the positive divisors of n. Find the following. (For each answer, enter an exact number.) (a) s(1) = (b) s(15) = (c) S(17) = (d) s(7) = (e) S(18) = (f) S(21) =