What is the Greatest Common Factor of 978 and 991?

Greatest common factor (GCF) of 978 and 991 is 1.

GCF(978,991) = 1

We will now calculate the prime factors of 978 and 991, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 978 and 991.

How to find the GCF of 978 and 991?

We will first find the prime factorization of 978 and 991. After we will calculate the factors of 978 and 991 and find the biggest common factor number .

Step-1: Prime Factorization of 978

Prime factors of 978 are 2, 3, 163. Prime factorization of 978 in exponential form is:

978 = 2¹ × 3¹ × 163¹

Step-2: Prime Factorization of 991

Prime factors of 991 are 991. Prime factorization of 991 in exponential form is:

991 = 991¹

Step-3: Factors of 978

List of positive integer factors of 978 that divides 978 without a remainder.

1, 2, 3, 6, 163, 326, 489

Step-4: Factors of 991

List of positive integer factors of 991 that divides 978 without a remainder.

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 978 and 991. The biggest common factor number is the GCF number.
So the greatest common factor 978 and 991 is 1.

Also check out the Least Common Multiple of 978 and 991