What is the Greatest Common Factor of 21857 and 21868?

Greatest common factor (GCF) of 21857 and 21868 is 11.

GCF(21857,21868) = 11

We will now calculate the prime factors of 21857 and 21868, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21857 and 21868.

How to find the GCF of 21857 and 21868?

We will first find the prime factorization of 21857 and 21868. After we will calculate the factors of 21857 and 21868 and find the biggest common factor number .

Step-1: Prime Factorization of 21857

Prime factors of 21857 are 11, 1987. Prime factorization of 21857 in exponential form is:

21857 = 11¹ × 1987¹

Step-2: Prime Factorization of 21868

Prime factors of 21868 are 2, 7, 11, 71. Prime factorization of 21868 in exponential form is:

21868 = 2² × 7¹ × 11¹ × 71¹

Step-3: Factors of 21857

List of positive integer factors of 21857 that divides 21857 without a remainder.

1, 11, 1987

Step-4: Factors of 21868

List of positive integer factors of 21868 that divides 21857 without a remainder.

1, 2, 4, 7, 11, 14, 22, 28, 44, 71, 77, 142, 154, 284, 308, 497, 781, 994, 1562, 1988, 3124, 5467, 10934

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21857 and 21868. The biggest common factor number is the GCF number.
So the greatest common factor 21857 and 21868 is 11.

Also check out the Least Common Multiple of 21857 and 21868