What is the Greatest Common Factor of 621 and 628?

Greatest common factor (GCF) of 621 and 628 is 1.

GCF(621,628) = 1

We will now calculate the prime factors of 621 and 628, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 621 and 628.

How to find the GCF of 621 and 628?

We will first find the prime factorization of 621 and 628. After we will calculate the factors of 621 and 628 and find the biggest common factor number .

Step-1: Prime Factorization of 621

Prime factors of 621 are 3, 23. Prime factorization of 621 in exponential form is:

621 = 3³ × 23¹

Step-2: Prime Factorization of 628

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

628 = 2² × 157¹

Step-3: Factors of 621

List of positive integer factors of 621 that divides 621 without a remainder.

1, 3, 9, 23, 27, 69, 207

Step-4: Factors of 628

List of positive integer factors of 628 that divides 621 without a remainder.

1, 2, 4, 157, 314

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 621 and 628. The biggest common factor number is the GCF number.
So the greatest common factor 621 and 628 is 1.

Also check out the Least Common Multiple of 621 and 628