What is the Greatest Common Factor of 3855 and 3870?

Greatest common factor (GCF) of 3855 and 3870 is 15.

GCF(3855,3870) = 15

We will now calculate the prime factors of 3855 and 3870, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 3855 and 3870.

How to find the GCF of 3855 and 3870?

We will first find the prime factorization of 3855 and 3870. After we will calculate the factors of 3855 and 3870 and find the biggest common factor number .

Step-1: Prime Factorization of 3855

Prime factors of 3855 are 3, 5, 257. Prime factorization of 3855 in exponential form is:

3855 = 3¹ × 5¹ × 257¹

Step-2: Prime Factorization of 3870

Prime factors of 3870 are 2, 3, 5, 43. Prime factorization of 3870 in exponential form is:

3870 = 2¹ × 3² × 5¹ × 43¹

Step-3: Factors of 3855

List of positive integer factors of 3855 that divides 3855 without a remainder.

1, 3, 5, 15, 257, 771, 1285

Step-4: Factors of 3870

List of positive integer factors of 3870 that divides 3855 without a remainder.

1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 43, 45, 86, 90, 129, 215, 258, 387, 430, 645, 774, 1290, 1935

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 3855 and 3870. The biggest common factor number is the GCF number.
So the greatest common factor 3855 and 3870 is 15.

Also check out the Least Common Multiple of 3855 and 3870