import math


def number_of_divisors(input_number):
    """Returns the number of divisors of input_number"""
    res = 0

    # check for square root divisor
    if math.sqrt(input_number) % 1 == 0:
        res += 1

    # check for other integer divisors
    for num in range(1, int(math.ceil(math.sqrt(input_number)))):
        if input_number % num == 0:
            res += 2

    return res