What is the Greatest Common Factor of 649 and 665?

Greatest common factor (GCF) of 649 and 665 is 1.

GCF(649,665) = 1

We will now calculate the prime factors of 649 and 665, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 649 and 665.

How to find the GCF of 649 and 665?

We will first find the prime factorization of 649 and 665. After we will calculate the factors of 649 and 665 and find the biggest common factor number .

Step-1: Prime Factorization of 649

Prime factors of 649 are 11, 59. Prime factorization of 649 in exponential form is:

649 = 11¹ × 59¹

Step-2: Prime Factorization of 665

Prime factors of 665 are 5, 7, 19. Prime factorization of 665 in exponential form is:

665 = 5¹ × 7¹ × 19¹

Step-3: Factors of 649

List of positive integer factors of 649 that divides 649 without a remainder.

1, 11, 59

Step-4: Factors of 665

List of positive integer factors of 665 that divides 649 without a remainder.

1, 5, 7, 19, 35, 95, 133

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 649 and 665. The biggest common factor number is the GCF number.
So the greatest common factor 649 and 665 is 1.

Also check out the Least Common Multiple of 649 and 665