What is the Greatest Common Factor of 209 and 220?

Greatest common factor (GCF) of 209 and 220 is 11.

GCF(209,220) = 11

We will now calculate the prime factors of 209 and 220, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 209 and 220.

How to find the GCF of 209 and 220?

We will first find the prime factorization of 209 and 220. After we will calculate the factors of 209 and 220 and find the biggest common factor number .

Step-1: Prime Factorization of 209

Prime factors of 209 are 11, 19. Prime factorization of 209 in exponential form is:

209 = 11¹ × 19¹

Step-2: Prime Factorization of 220

Prime factors of 220 are 2, 5, 11. Prime factorization of 220 in exponential form is:

220 = 2² × 5¹ × 11¹

Step-3: Factors of 209

List of positive integer factors of 209 that divides 209 without a remainder.

1, 11, 19

Step-4: Factors of 220

List of positive integer factors of 220 that divides 209 without a remainder.

1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 209 and 220. The biggest common factor number is the GCF number.
So the greatest common factor 209 and 220 is 11.

Also check out the Least Common Multiple of 209 and 220