What is the Greatest Common Factor of 686 and 691?

Greatest common factor (GCF) of 686 and 691 is 1.

GCF(686,691) = 1

We will now calculate the prime factors of 686 and 691, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 686 and 691.

How to find the GCF of 686 and 691?

We will first find the prime factorization of 686 and 691. After we will calculate the factors of 686 and 691 and find the biggest common factor number .

Step-1: Prime Factorization of 686

Prime factors of 686 are 2, 7. Prime factorization of 686 in exponential form is:

686 = 2¹ × 7³

Step-2: Prime Factorization of 691

Prime factors of 691 are 691. Prime factorization of 691 in exponential form is:

691 = 691¹

Step-3: Factors of 686

List of positive integer factors of 686 that divides 686 without a remainder.

1, 2, 7, 14, 49, 98, 343

Step-4: Factors of 691

List of positive integer factors of 691 that divides 686 without a remainder.

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 686 and 691. The biggest common factor number is the GCF number.
So the greatest common factor 686 and 691 is 1.

Also check out the Least Common Multiple of 686 and 691