Greatest Common Factor of 640 and 645

Created By : Jatin Gogia

Reviewed By : Rajasekhar Valipishetty

Last Updated : Apr 06, 2023

Make use of GCF Calculator to quickly find the Greatest Common Factor of numbers 640, 645 i.e. 5 largest integer by which both the numbers can be divided.

Greatest common factor (GCF) of 640 and 645 is 5.

GCF(640,645) = 5

GCF of 640 and 645

Greatest common factor or Greatest common divisor (GCD) can be calculated in following way;

GCF of:
and

Greatest Common Factor of 640 and 645

GCF of 640 and 645 is 5

Prime Factorization of 640


2 640
2 320
2 160
2 80
2 40
2 20
2 10
5 5
1

Prime factors of 640 are 2,5. Prime factorization of 640 in exponential form is:

640 = 27×51

Prime Factorization of 645


3 645
5 215
43 43
1

Prime factors of 645 are 3,5,43. Prime factorization of 645 in exponential form is:

645 = 31×51×431

∴ So by taking common prime factors GCF of 640 and 645 is 5

Greatest Common Factor of 640 and 645 by matching factors method

Factors of 640

List of positive integer factors of 640 that divides 640 without a remainder.

1,2,4,5,8,10,16,20,32,40,64,80,128,160,320,640

Factors of 645

List of positive integer factors of 645 that divides 645 without a remainder.

1,3,5,15,43,129,215,645

Greatest Common Factor

We found the factors and prime factorization of 640 and 645. The biggest common factor number is the GCF number.
So the greatest common factor 640 and 645 is 5.

Also check out the Least Common Multiple of 640 and 645

Properties of GCF 640 and 645

(i) The GCF of 640 and 645 is associative

GCF of 640 and 645 = GCF of 645 and 640

Related Greatest Common Factor of 640

Related Greatest Common Factor of 645

Frequently Asked Questions on GCF of 640 and 645

1. What is the GCF of 640 and 645?

Answer: GCF of 640 and 645 is 5.

2. What are the Factors of 640?

Answer: Factors of 640 are 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 128, 160, 320, 640. There are 16 integers that are factors of 640. The greatest factor of 640 is 640.

3. What are the Factors of 645?

Answer: Factors of 645 are 1, 3, 5, 15, 43, 129, 215, 645. There are 8 integers that are factors of 645. The greatest factor of 645 is 645.

4. How to Find the GCF of 640 and 645?

Answer:

Greatest Common Factor of 640 and 645 = 5

Step 1: Find the prime factorization of 640

640 = 2 x 2 x 2 x 2 x 2 x 2 x 2 x 5

Step 2: Find the prime factorization of 645

645 = 3 x 5 x 43

Step 3: Multiply those factors both numbers have in common in steps i) or ii) above to find the gcf:

GCF = 5

Step 4: Therefore, the greatest common factor of 640 and 645 is 5