What is the Greatest Common Factor of 21438 and 21447?

Greatest common factor (GCF) of 21438 and 21447 is 9.

GCF(21438,21447) = 9

We will now calculate the prime factors of 21438 and 21447, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21438 and 21447.

How to find the GCF of 21438 and 21447?

We will first find the prime factorization of 21438 and 21447. After we will calculate the factors of 21438 and 21447 and find the biggest common factor number .

Step-1: Prime Factorization of 21438

Prime factors of 21438 are 2, 3, 397. Prime factorization of 21438 in exponential form is:

21438 = 2¹ × 3³ × 397¹

Step-2: Prime Factorization of 21447

Prime factors of 21447 are 3, 2383. Prime factorization of 21447 in exponential form is:

21447 = 3² × 2383¹

Step-3: Factors of 21438

List of positive integer factors of 21438 that divides 21438 without a remainder.

1, 2, 3, 6, 9, 18, 27, 54, 397, 794, 1191, 2382, 3573, 7146, 10719

Step-4: Factors of 21447

List of positive integer factors of 21447 that divides 21438 without a remainder.

1, 3, 9, 2383, 7149

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21438 and 21447. The biggest common factor number is the GCF number.
So the greatest common factor 21438 and 21447 is 9.

Also check out the Least Common Multiple of 21438 and 21447