What is the Greatest Common Factor of 165 and 180?

Greatest common factor (GCF) of 165 and 180 is 15.

GCF(165,180) = 15

We will now calculate the prime factors of 165 and 180, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 165 and 180.

How to find the GCF of 165 and 180?

We will first find the prime factorization of 165 and 180. After we will calculate the factors of 165 and 180 and find the biggest common factor number .

Step-1: Prime Factorization of 165

Prime factors of 165 are 3, 5, 11. Prime factorization of 165 in exponential form is:

165 = 3¹ × 5¹ × 11¹

Step-2: Prime Factorization of 180

Prime factors of 180 are 2, 3, 5. Prime factorization of 180 in exponential form is:

180 = 2² × 3² × 5¹

Step-3: Factors of 165

List of positive integer factors of 165 that divides 165 without a remainder.

1, 3, 5, 11, 15, 33, 55

Step-4: Factors of 180

List of positive integer factors of 180 that divides 165 without a remainder.

1, 2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 30, 36, 45, 60, 90

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 165 and 180. The biggest common factor number is the GCF number.
So the greatest common factor 165 and 180 is 15.

Also check out the Least Common Multiple of 165 and 180