What is the Greatest Common Factor of 20811 and 20820?

Greatest common factor (GCF) of 20811 and 20820 is 3.

GCF(20811,20820) = 3

We will now calculate the prime factors of 20811 and 20820, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 20811 and 20820.

How to find the GCF of 20811 and 20820?

We will first find the prime factorization of 20811 and 20820. After we will calculate the factors of 20811 and 20820 and find the biggest common factor number .

Step-1: Prime Factorization of 20811

Prime factors of 20811 are 3, 7, 991. Prime factorization of 20811 in exponential form is:

20811 = 3¹ × 7¹ × 991¹

Step-2: Prime Factorization of 20820

Prime factors of 20820 are 2, 3, 5, 347. Prime factorization of 20820 in exponential form is:

20820 = 2² × 3¹ × 5¹ × 347¹

Step-3: Factors of 20811

List of positive integer factors of 20811 that divides 20811 without a remainder.

1, 3, 7, 21, 991, 2973, 6937

Step-4: Factors of 20820

List of positive integer factors of 20820 that divides 20811 without a remainder.

1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60, 347, 694, 1041, 1388, 1735, 2082, 3470, 4164, 5205, 6940, 10410

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 20811 and 20820. The biggest common factor number is the GCF number.
So the greatest common factor 20811 and 20820 is 3.

Also check out the Least Common Multiple of 20811 and 20820