What is the Greatest Common Factor of 1242 and 1257?

Greatest common factor (GCF) of 1242 and 1257 is 3.

GCF(1242,1257) = 3

We will now calculate the prime factors of 1242 and 1257, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 1242 and 1257.

How to find the GCF of 1242 and 1257?

We will first find the prime factorization of 1242 and 1257. After we will calculate the factors of 1242 and 1257 and find the biggest common factor number .

Step-1: Prime Factorization of 1242

Prime factors of 1242 are 2, 3, 23. Prime factorization of 1242 in exponential form is:

1242 = 2¹ × 3³ × 23¹

Step-2: Prime Factorization of 1257

Prime factors of 1257 are 3, 419. Prime factorization of 1257 in exponential form is:

1257 = 3¹ × 419¹

Step-3: Factors of 1242

List of positive integer factors of 1242 that divides 1242 without a remainder.

1, 2, 3, 6, 9, 18, 23, 27, 46, 54, 69, 138, 207, 414, 621

Step-4: Factors of 1257

List of positive integer factors of 1257 that divides 1242 without a remainder.

1, 3, 419

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 1242 and 1257. The biggest common factor number is the GCF number.
So the greatest common factor 1242 and 1257 is 3.

Also check out the Least Common Multiple of 1242 and 1257