What is the Greatest Common Factor of 21855 and 21873?

Greatest common factor (GCF) of 21855 and 21873 is 3.

GCF(21855,21873) = 3

We will now calculate the prime factors of 21855 and 21873, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21855 and 21873.

How to find the GCF of 21855 and 21873?

We will first find the prime factorization of 21855 and 21873. After we will calculate the factors of 21855 and 21873 and find the biggest common factor number .

Step-1: Prime Factorization of 21855

Prime factors of 21855 are 3, 5, 31, 47. Prime factorization of 21855 in exponential form is:

21855 = 3¹ × 5¹ × 31¹ × 47¹

Step-2: Prime Factorization of 21873

Prime factors of 21873 are 3, 23, 317. Prime factorization of 21873 in exponential form is:

21873 = 3¹ × 23¹ × 317¹

Step-3: Factors of 21855

List of positive integer factors of 21855 that divides 21855 without a remainder.

1, 3, 5, 15, 31, 47, 93, 141, 155, 235, 465, 705, 1457, 4371, 7285

Step-4: Factors of 21873

List of positive integer factors of 21873 that divides 21855 without a remainder.

1, 3, 23, 69, 317, 951, 7291

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21855 and 21873. The biggest common factor number is the GCF number.
So the greatest common factor 21855 and 21873 is 3.

Also check out the Least Common Multiple of 21855 and 21873