What is the Greatest Common Factor of 861 and 868?

Greatest common factor (GCF) of 861 and 868 is 7.

GCF(861,868) = 7

We will now calculate the prime factors of 861 and 868, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 861 and 868.

How to find the GCF of 861 and 868?

We will first find the prime factorization of 861 and 868. After we will calculate the factors of 861 and 868 and find the biggest common factor number .

Step-1: Prime Factorization of 861

Prime factors of 861 are 3, 7, 41. Prime factorization of 861 in exponential form is:

861 = 3¹ × 7¹ × 41¹

Step-2: Prime Factorization of 868

Prime factors of 868 are 2, 7, 31. Prime factorization of 868 in exponential form is:

868 = 2² × 7¹ × 31¹

Step-3: Factors of 861

List of positive integer factors of 861 that divides 861 without a remainder.

1, 3, 7, 21, 41, 123, 287

Step-4: Factors of 868

List of positive integer factors of 868 that divides 861 without a remainder.

1, 2, 4, 7, 14, 28, 31, 62, 124, 217, 434

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 861 and 868. The biggest common factor number is the GCF number.
So the greatest common factor 861 and 868 is 7.

Also check out the Least Common Multiple of 861 and 868