What is the Greatest Common Factor of 1540 and 1555?

Greatest common factor (GCF) of 1540 and 1555 is 5.

GCF(1540,1555) = 5

We will now calculate the prime factors of 1540 and 1555, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 1540 and 1555.

How to find the GCF of 1540 and 1555?

We will first find the prime factorization of 1540 and 1555. After we will calculate the factors of 1540 and 1555 and find the biggest common factor number .

Step-1: Prime Factorization of 1540

Prime factors of 1540 are 2, 5, 7, 11. Prime factorization of 1540 in exponential form is:

1540 = 2² × 5¹ × 7¹ × 11¹

Step-2: Prime Factorization of 1555

Prime factors of 1555 are 5, 311. Prime factorization of 1555 in exponential form is:

1555 = 5¹ × 311¹

Step-3: Factors of 1540

List of positive integer factors of 1540 that divides 1540 without a remainder.

1, 2, 4, 5, 7, 10, 11, 14, 20, 22, 28, 35, 44, 55, 70, 77, 110, 140, 154, 220, 308, 385, 770

Step-4: Factors of 1555

List of positive integer factors of 1555 that divides 1540 without a remainder.

1, 5, 311

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 1540 and 1555. The biggest common factor number is the GCF number.
So the greatest common factor 1540 and 1555 is 5.

Also check out the Least Common Multiple of 1540 and 1555