If n ≤ 0, return false.
While n is divisible by 2, divide n by 2.
While n is divisible by 3, divide n by 3.
While n is divisible by 5, divide n by 5.
If n == 1, return true. Otherwise, return false.
(Divide and check remainder)
If n ≤ 0, return false.
While n is divisible by 2, divide n by 2.
While n is divisible by 3, divide n by 3.
While n is divisible by 5, divide n by 5.
If n == 1, return true. Otherwise, return false.