What is the Greatest Common Factor of 1640 and 1645?

Greatest common factor (GCF) of 1640 and 1645 is 5.

GCF(1640,1645) = 5

We will now calculate the prime factors of 1640 and 1645, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 1640 and 1645.

How to find the GCF of 1640 and 1645?

We will first find the prime factorization of 1640 and 1645. After we will calculate the factors of 1640 and 1645 and find the biggest common factor number .

Step-1: Prime Factorization of 1640

Prime factors of 1640 are 2, 5, 41. Prime factorization of 1640 in exponential form is:

1640 = 2³ × 5¹ × 41¹

Step-2: Prime Factorization of 1645

Prime factors of 1645 are 5, 7, 47. Prime factorization of 1645 in exponential form is:

1645 = 5¹ × 7¹ × 47¹

Step-3: Factors of 1640

List of positive integer factors of 1640 that divides 1640 without a remainder.

1, 2, 4, 5, 8, 10, 20, 40, 41, 82, 164, 205, 328, 410, 820

Step-4: Factors of 1645

List of positive integer factors of 1645 that divides 1640 without a remainder.

1, 5, 7, 35, 47, 235, 329

Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 1640 and 1645. The biggest common factor number is the GCF number.
So the greatest common factor 1640 and 1645 is 5.

Also check out the Least Common Multiple of 1640 and 1645