What is the Greatest Common Factor of 20961 and 20979?

Greatest common factor (GCF) of 20961 and 20979 is 9.

GCF(20961,20979) = 9

We will now calculate the prime factors of 20961 and 20979, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 20961 and 20979.

How to find the GCF of 20961 and 20979?

We will first find the prime factorization of 20961 and 20979. After we will calculate the factors of 20961 and 20979 and find the biggest common factor number .

Step-1: Prime Factorization of 20961

Prime factors of 20961 are 3, 17, 137. Prime factorization of 20961 in exponential form is:

20961 = 3² × 17¹ × 137¹

Step-2: Prime Factorization of 20979

Prime factors of 20979 are 3, 7, 37. Prime factorization of 20979 in exponential form is:

20979 = 3⁴ × 7¹ × 37¹

Step-3: Factors of 20961

List of positive integer factors of 20961 that divides 20961 without a remainder.

1, 3, 9, 17, 51, 137, 153, 411, 1233, 2329, 6987

Step-4: Factors of 20979

List of positive integer factors of 20979 that divides 20961 without a remainder.

1, 3, 7, 9, 21, 27, 37, 63, 81, 111, 189, 259, 333, 567, 777, 999, 2331, 2997, 6993

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 20961 and 20979. The biggest common factor number is the GCF number.
So the greatest common factor 20961 and 20979 is 9.

Also check out the Least Common Multiple of 20961 and 20979