What is the Greatest Common Factor of 1140 and 1155?

Greatest common factor (GCF) of 1140 and 1155 is 15.

GCF(1140,1155) = 15

We will now calculate the prime factors of 1140 and 1155, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 1140 and 1155.

How to find the GCF of 1140 and 1155?

We will first find the prime factorization of 1140 and 1155. After we will calculate the factors of 1140 and 1155 and find the biggest common factor number .

Step-1: Prime Factorization of 1140

Prime factors of 1140 are 2, 3, 5, 19. Prime factorization of 1140 in exponential form is:

1140 = 2² × 3¹ × 5¹ × 19¹

Step-2: Prime Factorization of 1155

Prime factors of 1155 are 3, 5, 7, 11. Prime factorization of 1155 in exponential form is:

1155 = 3¹ × 5¹ × 7¹ × 11¹

Step-3: Factors of 1140

List of positive integer factors of 1140 that divides 1140 without a remainder.

1, 2, 3, 4, 5, 6, 10, 12, 15, 19, 20, 30, 38, 57, 60, 76, 95, 114, 190, 228, 285, 380, 570

Step-4: Factors of 1155

List of positive integer factors of 1155 that divides 1140 without a remainder.

1, 3, 5, 7, 11, 15, 21, 33, 35, 55, 77, 105, 165, 231, 385

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 1140 and 1155. The biggest common factor number is the GCF number.
So the greatest common factor 1140 and 1155 is 15.

Also check out the Least Common Multiple of 1140 and 1155