What is the Greatest Common Factor of 639 and 655?

Greatest common factor (GCF) of 639 and 655 is 1.

GCF(639,655) = 1

We will now calculate the prime factors of 639 and 655, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 639 and 655.

How to find the GCF of 639 and 655?

We will first find the prime factorization of 639 and 655. After we will calculate the factors of 639 and 655 and find the biggest common factor number .

Step-1: Prime Factorization of 639

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

639 = 3² × 71¹

Step-2: Prime Factorization of 655

Prime factors of 655 are 5, 131. Prime factorization of 655 in exponential form is:

655 = 5¹ × 131¹

Step-3: Factors of 639

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

1, 3, 9, 71, 213

Step-4: Factors of 655

List of positive integer factors of 655 that divides 639 without a remainder.

1, 5, 131

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 639 and 655. The biggest common factor number is the GCF number.
So the greatest common factor 639 and 655 is 1.

Also check out the Least Common Multiple of 639 and 655