What is the Greatest Common Factor of 21781 and 21785?

Greatest common factor (GCF) of 21781 and 21785 is 1.

GCF(21781,21785) = 1

We will now calculate the prime factors of 21781 and 21785, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 21781 and 21785.

How to find the GCF of 21781 and 21785?

We will first find the prime factorization of 21781 and 21785. After we will calculate the factors of 21781 and 21785 and find the biggest common factor number .

Step-1: Prime Factorization of 21781

Prime factors of 21781 are 23, 947. Prime factorization of 21781 in exponential form is:

21781 = 23¹ × 947¹

Step-2: Prime Factorization of 21785

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

21785 = 5¹ × 4357¹

Step-3: Factors of 21781

List of positive integer factors of 21781 that divides 21781 without a remainder.

1, 23, 947

Step-4: Factors of 21785

List of positive integer factors of 21785 that divides 21781 without a remainder.

1, 5, 4357

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 21781 and 21785. The biggest common factor number is the GCF number.
So the greatest common factor 21781 and 21785 is 1.

Also check out the Least Common Multiple of 21781 and 21785