What is the Greatest Common Factor of 21785 and 21805?

Greatest common factor (GCF) of 21785 and 21805 is 5.

GCF(21785,21805) = 5

We will now calculate the prime factors of 21785 and 21805, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21785 and 21805.

How to find the GCF of 21785 and 21805?

We will first find the prime factorization of 21785 and 21805. After we will calculate the factors of 21785 and 21805 and find the biggest common factor number .

Step-1: Prime Factorization of 21785

Prime factors of 21785 are 5, 4357. Prime factorization of 21785 in exponential form is:

21785 = 5¹ × 4357¹

Step-2: 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-3: Factors of 21785

List of positive integer factors of 21785 that divides 21785 without a remainder.

1, 5, 4357

Step-4: Factors of 21805

List of positive integer factors of 21805 that divides 21785 without a remainder.

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

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21785 and 21805. The biggest common factor number is the GCF number.
So the greatest common factor 21785 and 21805 is 5.

Also check out the Least Common Multiple of 21785 and 21805