What is the Greatest Common Factor of 628 and 640?

Greatest common factor (GCF) of 628 and 640 is 4.

GCF(628,640) = 4

We will now calculate the prime factors of 628 and 640, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 628 and 640.

How to find the GCF of 628 and 640?

We will first find the prime factorization of 628 and 640. After we will calculate the factors of 628 and 640 and find the biggest common factor number .

Step-1: Prime Factorization of 628

Prime factors of 628 are 2, 157. Prime factorization of 628 in exponential form is:

628 = 2² × 157¹

Step-2: Prime Factorization of 640

Prime factors of 640 are 2, 5. Prime factorization of 640 in exponential form is:

640 = 2⁷ × 5¹

Step-3: Factors of 628

List of positive integer factors of 628 that divides 628 without a remainder.

1, 2, 4, 157, 314

Step-4: Factors of 640

List of positive integer factors of 640 that divides 628 without a remainder.

1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 128, 160, 320

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 628 and 640. The biggest common factor number is the GCF number.
So the greatest common factor 628 and 640 is 4.

Also check out the Least Common Multiple of 628 and 640