count-the-divisors-of-a-number

Count the divisors of a number

Count the number of divisors of a positive integer n.

Random tests go up to n = 500000.

Examples

divisors(4) -> 3 -- 1, 2, 4
divisors(5) -> 2 -- 1, 5
divisors(12) -> 6 -- 1, 2, 3, 4, 6, 12
divisors(30) -> 8 -- 1, 2, 3, 5, 6, 10, 15, 30