What is the Greatest Common Factor of 21978 and 21997?

Greatest common factor (GCF) of 21978 and 21997 is 1.

GCF(21978,21997) = 1

We will now calculate the prime factors of 21978 and 21997, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21978 and 21997.

How to find the GCF of 21978 and 21997?

We will first find the prime factorization of 21978 and 21997. After we will calculate the factors of 21978 and 21997 and find the biggest common factor number .

Step-1: Prime Factorization of 21978

Prime factors of 21978 are 2, 3, 11, 37. Prime factorization of 21978 in exponential form is:

21978 = 2¹ × 3³ × 11¹ × 37¹

Step-2: Prime Factorization of 21997

Prime factors of 21997 are 21997. Prime factorization of 21997 in exponential form is:

21997 = 21997¹

Step-3: Factors of 21978

List of positive integer factors of 21978 that divides 21978 without a remainder.

1, 2, 3, 6, 9, 11, 18, 22, 27, 33, 37, 54, 66, 74, 99, 111, 198, 222, 297, 333, 407, 594, 666, 814, 999, 1221, 1998, 2442, 3663, 7326, 10989

Step-4: Factors of 21997

List of positive integer factors of 21997 that divides 21978 without a remainder.

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21978 and 21997. The biggest common factor number is the GCF number.
So the greatest common factor 21978 and 21997 is 1.

Also check out the Least Common Multiple of 21978 and 21997