What is the Greatest Common Factor of 19809 and 19821?

Greatest common factor (GCF) of 19809 and 19821 is 3.

GCF(19809,19821) = 3

We will now calculate the prime factors of 19809 and 19821, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 19809 and 19821.

How to find the GCF of 19809 and 19821?

We will first find the prime factorization of 19809 and 19821. After we will calculate the factors of 19809 and 19821 and find the biggest common factor number .

Step-1: Prime Factorization of 19809

Prime factors of 19809 are 3, 31, 71. Prime factorization of 19809 in exponential form is:

19809 = 3² × 31¹ × 71¹

Step-2: Prime Factorization of 19821

Prime factors of 19821 are 3, 6607. Prime factorization of 19821 in exponential form is:

19821 = 3¹ × 6607¹

Step-3: Factors of 19809

List of positive integer factors of 19809 that divides 19809 without a remainder.

1, 3, 9, 31, 71, 93, 213, 279, 639, 2201, 6603

Step-4: Factors of 19821

List of positive integer factors of 19821 that divides 19809 without a remainder.

1, 3, 6607

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 19809 and 19821. The biggest common factor number is the GCF number.
So the greatest common factor 19809 and 19821 is 3.

Also check out the Least Common Multiple of 19809 and 19821