What is the Greatest Common Factor of 81985 and 81990?

Greatest common factor (GCF) of 81985 and 81990 is 5.

GCF(81985,81990) = 5

We will now calculate the prime factors of 81985 and 81990, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 81985 and 81990.

How to find the GCF of 81985 and 81990?

We will first find the prime factorization of 81985 and 81990. After we will calculate the factors of 81985 and 81990 and find the biggest common factor number .

Step-1: Prime Factorization of 81985

Prime factors of 81985 are 5, 19, 863. Prime factorization of 81985 in exponential form is:

81985 = 5¹ × 19¹ × 863¹

Step-2: Prime Factorization of 81990

Prime factors of 81990 are 2, 3, 5, 911. Prime factorization of 81990 in exponential form is:

81990 = 2¹ × 3² × 5¹ × 911¹

Step-3: Factors of 81985

List of positive integer factors of 81985 that divides 81985 without a remainder.

1, 5, 19, 95, 863, 4315, 16397

Step-4: Factors of 81990

List of positive integer factors of 81990 that divides 81985 without a remainder.

1, 2, 3, 5, 6, 9, 10, 15, 18, 30, 45, 90, 911, 1822, 2733, 4555, 5466, 8199, 9110, 13665, 16398, 27330, 40995

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 81985 and 81990. The biggest common factor number is the GCF number.
So the greatest common factor 81985 and 81990 is 5.

Also check out the Least Common Multiple of 81985 and 81990