What is the Greatest Common Factor of 19990 and 19998?

Greatest common factor (GCF) of 19990 and 19998 is 2.

GCF(19990,19998) = 2

We will now calculate the prime factors of 19990 and 19998, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 19990 and 19998.

How to find the GCF of 19990 and 19998?

We will first find the prime factorization of 19990 and 19998. After we will calculate the factors of 19990 and 19998 and find the biggest common factor number .

Step-1: Prime Factorization of 19990

Prime factors of 19990 are 2, 5, 1999. Prime factorization of 19990 in exponential form is:

19990 = 2¹ × 5¹ × 1999¹

Step-2: Prime Factorization of 19998

Prime factors of 19998 are 2, 3, 11, 101. Prime factorization of 19998 in exponential form is:

19998 = 2¹ × 3² × 11¹ × 101¹

Step-3: Factors of 19990

List of positive integer factors of 19990 that divides 19990 without a remainder.

1, 2, 5, 10, 1999, 3998, 9995

Step-4: Factors of 19998

List of positive integer factors of 19998 that divides 19990 without a remainder.

1, 2, 3, 6, 9, 11, 18, 22, 33, 66, 99, 101, 198, 202, 303, 606, 909, 1111, 1818, 2222, 3333, 6666, 9999

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 19990 and 19998. The biggest common factor number is the GCF number.
So the greatest common factor 19990 and 19998 is 2.

Also check out the Least Common Multiple of 19990 and 19998