What is the Greatest Common Factor of 3900 and 3920?

Greatest common factor (GCF) of 3900 and 3920 is 20.

GCF(3900,3920) = 20

We will now calculate the prime factors of 3900 and 3920, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 3900 and 3920.

How to find the GCF of 3900 and 3920?

We will first find the prime factorization of 3900 and 3920. After we will calculate the factors of 3900 and 3920 and find the biggest common factor number .

Step-1: Prime Factorization of 3900

Prime factors of 3900 are 2, 3, 5, 13. Prime factorization of 3900 in exponential form is:

3900 = 2² × 3¹ × 5² × 13¹

Step-2: Prime Factorization of 3920

Prime factors of 3920 are 2, 5, 7. Prime factorization of 3920 in exponential form is:

3920 = 2⁴ × 5¹ × 7²

Step-3: Factors of 3900

List of positive integer factors of 3900 that divides 3900 without a remainder.

1, 2, 3, 4, 5, 6, 10, 12, 13, 15, 20, 25, 26, 30, 39, 50, 52, 60, 65, 75, 78, 100, 130, 150, 156, 195, 260, 300, 325, 390, 650, 780, 975, 1300, 1950

Step-4: Factors of 3920

List of positive integer factors of 3920 that divides 3900 without a remainder.

1, 2, 4, 5, 7, 8, 10, 14, 16, 20, 28, 35, 40, 49, 56, 70, 80, 98, 112, 140, 196, 245, 280, 392, 490, 560, 784, 980, 1960

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 3900 and 3920. The biggest common factor number is the GCF number.
So the greatest common factor 3900 and 3920 is 20.

Also check out the Least Common Multiple of 3900 and 3920