What is the Greatest Common Factor of 7920 and 7940?

Greatest common factor (GCF) of 7920 and 7940 is 20.

GCF(7920,7940) = 20

We will now calculate the prime factors of 7920 and 7940, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 7920 and 7940.

How to find the GCF of 7920 and 7940?

We will first find the prime factorization of 7920 and 7940. After we will calculate the factors of 7920 and 7940 and find the biggest common factor number .

Step-1: Prime Factorization of 7920

Prime factors of 7920 are 2, 3, 5, 11. Prime factorization of 7920 in exponential form is:

7920 = 2⁴ × 3² × 5¹ × 11¹

Step-2: Prime Factorization of 7940

Prime factors of 7940 are 2, 5, 397. Prime factorization of 7940 in exponential form is:

7940 = 2² × 5¹ × 397¹

Step-3: Factors of 7920

List of positive integer factors of 7920 that divides 7920 without a remainder.

1, 2, 3, 4, 5, 6, 8, 9, 10, 11, 12, 15, 16, 18, 20, 22, 24, 30, 33, 36, 40, 44, 45, 48, 55, 60, 66, 72, 80, 88, 90, 99, 110, 120, 132, 144, 165, 176, 180, 198, 220, 240, 264, 330, 360, 396, 440, 495, 528, 660, 720, 792, 880, 990, 1320, 1584, 1980, 2640, 3960

Step-4: Factors of 7940

List of positive integer factors of 7940 that divides 7920 without a remainder.

1, 2, 4, 5, 10, 20, 397, 794, 1588, 1985, 3970

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 7920 and 7940. The biggest common factor number is the GCF number.
So the greatest common factor 7920 and 7940 is 20.

Also check out the Least Common Multiple of 7920 and 7940