What is the Greatest Common Factor of 19987 and 20005?

Greatest common factor (GCF) of 19987 and 20005 is 1.

GCF(19987,20005) = 1

We will now calculate the prime factors of 19987 and 20005, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 19987 and 20005.

How to find the GCF of 19987 and 20005?

We will first find the prime factorization of 19987 and 20005. After we will calculate the factors of 19987 and 20005 and find the biggest common factor number .

Step-1: Prime Factorization of 19987

Prime factors of 19987 are 11, 23, 79. Prime factorization of 19987 in exponential form is:

19987 = 11¹ × 23¹ × 79¹

Step-2: Prime Factorization of 20005

Prime factors of 20005 are 5, 4001. Prime factorization of 20005 in exponential form is:

20005 = 5¹ × 4001¹

Step-3: Factors of 19987

List of positive integer factors of 19987 that divides 19987 without a remainder.

1, 11, 23, 79, 253, 869, 1817

Step-4: Factors of 20005

List of positive integer factors of 20005 that divides 19987 without a remainder.

1, 5, 4001

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 19987 and 20005. The biggest common factor number is the GCF number.
So the greatest common factor 19987 and 20005 is 1.

Also check out the Least Common Multiple of 19987 and 20005