What is the Greatest Common Factor of 1561 and 1581?

Greatest common factor (GCF) of 1561 and 1581 is 1.

GCF(1561,1581) = 1

We will now calculate the prime factors of 1561 and 1581, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 1561 and 1581.

How to find the GCF of 1561 and 1581?

We will first find the prime factorization of 1561 and 1581. After we will calculate the factors of 1561 and 1581 and find the biggest common factor number .

Step-1: Prime Factorization of 1561

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

1561 = 7¹ × 223¹

Step-2: Prime Factorization of 1581

Prime factors of 1581 are 3, 17, 31. Prime factorization of 1581 in exponential form is:

1581 = 3¹ × 17¹ × 31¹

Step-3: Factors of 1561

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

1, 7, 223

Step-4: Factors of 1581

List of positive integer factors of 1581 that divides 1561 without a remainder.

1, 3, 17, 31, 51, 93, 527

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 1561 and 1581. The biggest common factor number is the GCF number.
So the greatest common factor 1561 and 1581 is 1.

Also check out the Least Common Multiple of 1561 and 1581