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 642, 645 i.e. 3 largest integer by which both the numbers can be divided.
Greatest common factor (GCF) of 642 and 645 is 3.
GCF(642,645) = 3
Greatest common factor or Greatest common divisor (GCD) can be calculated in following way;
Prime Factorization of 642
2 | 642 |
3 | 321 |
107 | 107 |
1 |
Prime factors of 642 are 2,3,107. Prime factorization of 642 in exponential form is:
642 = 21×31×1071
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 642 and 645 is 3
Factors of 642
List of positive integer factors of 642 that divides 642 without a remainder.
1,2,3,6,107,214,321,642
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 642 and 645. The biggest common factor number is the GCF number.
So the greatest common factor 642 and 645 is 3.
Also check out the Least Common Multiple of 642 and 645
(i) The GCF of 642 and 645 is associative
GCF of 642 and 645 = GCF of 645 and 642
1. What is the GCF of 642 and 645?
Answer: GCF of 642 and 645 is 3.
2. What are the Factors of 642?
Answer: Factors of 642 are 1, 2, 3, 6, 107, 214, 321, 642. There are 8 integers that are factors of 642. The greatest factor of 642 is 642.
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 642 and 645?
Answer:
Greatest Common Factor of 642 and 645 = 3
Step 1: Find the prime factorization of 642
642 = 2 x 3 x 107
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 = 3
Step 4: Therefore, the greatest common factor of 642 and 645 is 3