What is the Greatest Common Factor of 21805 and 21816?

Greatest common factor (GCF) of 21805 and 21816 is 1.

GCF(21805,21816) = 1

We will now calculate the prime factors of 21805 and 21816, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21805 and 21816.

How to find the GCF of 21805 and 21816?

We will first find the prime factorization of 21805 and 21816. After we will calculate the factors of 21805 and 21816 and find the biggest common factor number .

Step-1: Prime Factorization of 21805

Prime factors of 21805 are 5, 7, 89. Prime factorization of 21805 in exponential form is:

21805 = 5¹ × 7² × 89¹

Step-2: Prime Factorization of 21816

Prime factors of 21816 are 2, 3, 101. Prime factorization of 21816 in exponential form is:

21816 = 2³ × 3³ × 101¹

Step-3: Factors of 21805

List of positive integer factors of 21805 that divides 21805 without a remainder.

1, 5, 7, 35, 49, 89, 245, 445, 623, 3115, 4361

Step-4: Factors of 21816

List of positive integer factors of 21816 that divides 21805 without a remainder.

1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 27, 36, 54, 72, 101, 108, 202, 216, 303, 404, 606, 808, 909, 1212, 1818, 2424, 2727, 3636, 5454, 7272, 10908

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21805 and 21816. The biggest common factor number is the GCF number.
So the greatest common factor 21805 and 21816 is 1.

Also check out the Least Common Multiple of 21805 and 21816