What is the Greatest Common Factor of 643 and 661?

Greatest common factor (GCF) of 643 and 661 is 1.

GCF(643,661) = 1

We will now calculate the prime factors of 643 and 661, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 643 and 661.

How to find the GCF of 643 and 661?

We will first find the prime factorization of 643 and 661. After we will calculate the factors of 643 and 661 and find the biggest common factor number .

Step-1: Prime Factorization of 643

Prime factors of 643 are 643. Prime factorization of 643 in exponential form is:

643 = 643¹

Step-2: Prime Factorization of 661

Prime factors of 661 are 661. Prime factorization of 661 in exponential form is:

661 = 661¹

Step-3: Factors of 643

List of positive integer factors of 643 that divides 643 without a remainder.

Step-4: Factors of 661

List of positive integer factors of 661 that divides 643 without a remainder.

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 643 and 661. The biggest common factor number is the GCF number.
So the greatest common factor 643 and 661 is 1.

Also check out the Least Common Multiple of 643 and 661