What is the Greatest Common Factor of 620 and 639?

Greatest common factor (GCF) of 620 and 639 is 1.

GCF(620,639) = 1

We will now calculate the prime factors of 620 and 639, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 620 and 639.

How to find the GCF of 620 and 639?

We will first find the prime factorization of 620 and 639. After we will calculate the factors of 620 and 639 and find the biggest common factor number .

Step-1: Prime Factorization of 620

Prime factors of 620 are 2, 5, 31. Prime factorization of 620 in exponential form is:

620 = 2² × 5¹ × 31¹

Step-2: Prime Factorization of 639

Prime factors of 639 are 3, 71. Prime factorization of 639 in exponential form is:

639 = 3² × 71¹

Step-3: Factors of 620

List of positive integer factors of 620 that divides 620 without a remainder.

1, 2, 4, 5, 10, 20, 31, 62, 124, 155, 310

Step-4: Factors of 639

List of positive integer factors of 639 that divides 620 without a remainder.

1, 3, 9, 71, 213

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 620 and 639. The biggest common factor number is the GCF number.
So the greatest common factor 620 and 639 is 1.

Also check out the Least Common Multiple of 620 and 639