What is the Greatest Common Factor of 21980 and 21988?

Greatest common factor (GCF) of 21980 and 21988 is 4.

GCF(21980,21988) = 4

We will now calculate the prime factors of 21980 and 21988, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21980 and 21988.

How to find the GCF of 21980 and 21988?

We will first find the prime factorization of 21980 and 21988. After we will calculate the factors of 21980 and 21988 and find the biggest common factor number .

Step-1: Prime Factorization of 21980

Prime factors of 21980 are 2, 5, 7, 157. Prime factorization of 21980 in exponential form is:

21980 = 2² × 5¹ × 7¹ × 157¹

Step-2: Prime Factorization of 21988

Prime factors of 21988 are 2, 23, 239. Prime factorization of 21988 in exponential form is:

21988 = 2² × 23¹ × 239¹

Step-3: Factors of 21980

List of positive integer factors of 21980 that divides 21980 without a remainder.

1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70, 140, 157, 314, 628, 785, 1099, 1570, 2198, 3140, 4396, 5495, 10990

Step-4: Factors of 21988

List of positive integer factors of 21988 that divides 21980 without a remainder.

1, 2, 4, 23, 46, 92, 239, 478, 956, 5497, 10994

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21980 and 21988. The biggest common factor number is the GCF number.
So the greatest common factor 21980 and 21988 is 4.

Also check out the Least Common Multiple of 21980 and 21988