def get_useful_factors(num):
    if (num < 2):
        return []
    factors = []
    for i in range(2, (MAX_KEY_LENGTH + 1)):
        if ((num % i) == 0):
            factors.append(i)
            other_factor = int((num / i))
            if ((other_factor < (MAX_KEY_LENGTH + 1)) and (other_factor != 1)):
                factors.append(other_factor)
    return list(set(factors))
def get_useful_factors(num):
    if (num < 2):
        return []
    factors = []
    for i in range(2, (MAX_KEY_LENGTH + 1)):
        if ((num % i) == 0):
            factors.append(i)
            other_factor = int((num / i))
            if ((other_factor < (MAX_KEY_LENGTH + 1)) and (other_factor != 1)):
                factors.append(other_factor)
    return list(set(factors))