Slow GCF Algorithm

import math

# how many numbers we're going to find the factors of
input_count = 0

# where the factors are being stored (2D array)
factors = []

# function for finding factors
def find_and_store(number=0):
        number = abs(number) if (number < 0 and number != 1) else 1 if (number == 0) else number

        # 1 and number are always factors
        n_factors = [1]

        # going through possible factors
        for i in range(2, number):
                for j in range(i, number):
                        product = i * j

                        # adding factor to list
                        if product == number:
                                n_factors.append(i)

                                # accounting for perfect squares
                                if (i != j):
                                        n_factors.append(j)
                                break
                        # if the product is greater then the number it isn't a factor
                        elif product > number:
                                break

                continue

        n_factors.append(number)
        factors.append(n_factors)


def calculate_gcf():
        primary_factors = factors[0]
        secondary_factors = factors[1]
        gcf = 0

        # slow check each factor
        for f1 in primary_factors:
                for f2 in secondary_factors:
                        if f1 == f2 and f1 > gcf:
                                gcf = f1
                                break

        return gcf




print("GCF Calculator - Slow Version\n")

while True:
        number = input("Enter integer to find factors: ")

        # any non-number will break out of the program
        try:
                # using an exception because I can't get isnan to work as it's suppose to and I just wanted to get this working
                math.isnan(float(number))
        except ValueError:
                break

        find_and_store(int(number))

# if more then one number was entered we can calculate a GCF
if len(factors) > 1:
        gcf = calculate_gcf()
        print(gcf)
else:
        print("Must provide at least two numbers to calculate a GCF")