What is the Greatest Common Factor of 21603 and 21609?

Greatest common factor (GCF) of 21603 and 21609 is 3.

GCF(21603,21609) = 3

We will now calculate the prime factors of 21603 and 21609, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21603 and 21609.

How to find the GCF of 21603 and 21609?

We will first find the prime factorization of 21603 and 21609. After we will calculate the factors of 21603 and 21609 and find the biggest common factor number .

Step-1: Prime Factorization of 21603

Prime factors of 21603 are 3, 19, 379. Prime factorization of 21603 in exponential form is:

21603 = 3¹ × 19¹ × 379¹

Step-2: Prime Factorization of 21609

Prime factors of 21609 are 3, 7. Prime factorization of 21609 in exponential form is:

21609 = 3² × 7⁴

Step-3: Factors of 21603

List of positive integer factors of 21603 that divides 21603 without a remainder.

1, 3, 19, 57, 379, 1137, 7201

Step-4: Factors of 21609

List of positive integer factors of 21609 that divides 21603 without a remainder.

1, 3, 7, 9, 21, 49, 63, 147, 343, 441, 1029, 2401, 3087, 7203

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21603 and 21609. The biggest common factor number is the GCF number.
So the greatest common factor 21603 and 21609 is 3.

Also check out the Least Common Multiple of 21603 and 21609