What is the Greatest Common Factor of 1978 and 1998?

Greatest common factor (GCF) of 1978 and 1998 is 2.

GCF(1978,1998) = 2

We will now calculate the prime factors of 1978 and 1998, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 1978 and 1998.

How to find the GCF of 1978 and 1998?

We will first find the prime factorization of 1978 and 1998. After we will calculate the factors of 1978 and 1998 and find the biggest common factor number .

Step-1: Prime Factorization of 1978

Prime factors of 1978 are 2, 23, 43. Prime factorization of 1978 in exponential form is:

1978 = 2¹ × 23¹ × 43¹

Step-2: Prime Factorization of 1998

Prime factors of 1998 are 2, 3, 37. Prime factorization of 1998 in exponential form is:

1998 = 2¹ × 3³ × 37¹

Step-3: Factors of 1978

List of positive integer factors of 1978 that divides 1978 without a remainder.

1, 2, 23, 43, 46, 86, 989

Step-4: Factors of 1998

List of positive integer factors of 1998 that divides 1978 without a remainder.

1, 2, 3, 6, 9, 18, 27, 37, 54, 74, 111, 222, 333, 666, 999

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 1978 and 1998. The biggest common factor number is the GCF number.
So the greatest common factor 1978 and 1998 is 2.

Also check out the Least Common Multiple of 1978 and 1998