What is the Greatest Common Factor of 1557 and 1561?

Greatest common factor (GCF) of 1557 and 1561 is 1.

GCF(1557,1561) = 1

We will now calculate the prime factors of 1557 and 1561, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 1557 and 1561.

How to find the GCF of 1557 and 1561?

We will first find the prime factorization of 1557 and 1561. After we will calculate the factors of 1557 and 1561 and find the biggest common factor number .

Step-1: Prime Factorization of 1557

Prime factors of 1557 are 3, 173. Prime factorization of 1557 in exponential form is:

1557 = 3² × 173¹

Step-2: Prime Factorization of 1561

Prime factors of 1561 are 7, 223. Prime factorization of 1561 in exponential form is:

1561 = 7¹ × 223¹

Step-3: Factors of 1557

List of positive integer factors of 1557 that divides 1557 without a remainder.

1, 3, 9, 173, 519

Step-4: Factors of 1561

List of positive integer factors of 1561 that divides 1557 without a remainder.

1, 7, 223

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 1557 and 1561. The biggest common factor number is the GCF number.
So the greatest common factor 1557 and 1561 is 1.

Also check out the Least Common Multiple of 1557 and 1561