What is the Greatest Common Factor of 21009 and 21020?

Greatest common factor (GCF) of 21009 and 21020 is 1.

GCF(21009,21020) = 1

We will now calculate the prime factors of 21009 and 21020, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21009 and 21020.

How to find the GCF of 21009 and 21020?

We will first find the prime factorization of 21009 and 21020. After we will calculate the factors of 21009 and 21020 and find the biggest common factor number .

Step-1: Prime Factorization of 21009

Prime factors of 21009 are 3, 47, 149. Prime factorization of 21009 in exponential form is:

21009 = 3¹ × 47¹ × 149¹

Step-2: Prime Factorization of 21020

Prime factors of 21020 are 2, 5, 1051. Prime factorization of 21020 in exponential form is:

21020 = 2² × 5¹ × 1051¹

Step-3: Factors of 21009

List of positive integer factors of 21009 that divides 21009 without a remainder.

1, 3, 47, 141, 149, 447, 7003

Step-4: Factors of 21020

List of positive integer factors of 21020 that divides 21009 without a remainder.

1, 2, 4, 5, 10, 20, 1051, 2102, 4204, 5255, 10510

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21009 and 21020. The biggest common factor number is the GCF number.
So the greatest common factor 21009 and 21020 is 1.

Also check out the Least Common Multiple of 21009 and 21020