What is the Greatest Common Factor of 12840 and 12855?

Greatest common factor (GCF) of 12840 and 12855 is 15.

GCF(12840,12855) = 15

We will now calculate the prime factors of 12840 and 12855, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 12840 and 12855.

How to find the GCF of 12840 and 12855?

We will first find the prime factorization of 12840 and 12855. After we will calculate the factors of 12840 and 12855 and find the biggest common factor number .

Step-1: Prime Factorization of 12840

Prime factors of 12840 are 2, 3, 5, 107. Prime factorization of 12840 in exponential form is:

12840 = 2³ × 3¹ × 5¹ × 107¹

Step-2: Prime Factorization of 12855

Prime factors of 12855 are 3, 5, 857. Prime factorization of 12855 in exponential form is:

12855 = 3¹ × 5¹ × 857¹

Step-3: Factors of 12840

List of positive integer factors of 12840 that divides 12840 without a remainder.

1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, 107, 120, 214, 321, 428, 535, 642, 856, 1070, 1284, 1605, 2140, 2568, 3210, 4280, 6420

Step-4: Factors of 12855

List of positive integer factors of 12855 that divides 12840 without a remainder.

1, 3, 5, 15, 857, 2571, 4285

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 12840 and 12855. The biggest common factor number is the GCF number.
So the greatest common factor 12840 and 12855 is 15.

Also check out the Least Common Multiple of 12840 and 12855