GCF for 100 and 645

What is the Greatest Common Factor of 100 and 645?

Answer: GCF of 100 and 645 is 5

(Five)

Finding GCF for 100 and 645 using all factors (divisors) listing

The first method to find GCF for numbers 100 and 645 is to list all factors for both numbers and pick the highest common one:

All factors of 100: 1, 2, 4, 5, 10, 20, 25, 50, 100

All factors of 645: 1, 3, 5, 15, 43, 129, 215, 645

So the Greatest Common Factor for 100 and 645 is 5

Finding GCF for 100 and 645 by Prime Factorization

The second method to find GCF for numbers 100 and 645 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 100: 2, 2, 5, 5

All Prime Factors of 645: 3, 5, 43

As we can see there is only one Prime Factor common to both numbers. It is 5

So 5 is the Greatest Common Factor of 100 and 645

GCF Table

Number 1Number 2GCF
856455
8664543
876453
886451
896451
9064515
916451
926451
936453
946451
956455
966453
976451
986451
996453
1006455
1016451
1026453
1036451
1046451
10564515
1066451
1076451
1086453
1096451
1106455
1116453
1126451
1136451
1146453

About "Greatest Common Factor" Calculator

This calculator will help you find the greatest common factor (GCF) of two numbers. For example, it can help you find out what is the Greatest Common Factor of 100 and 645? (The answer is: 5). Select the first number (e.g. '100') and the second number (e.g. '645'). After that hit the 'Calculate' button.
Greatest Common Factor (GCF) also known as the Greatest Common Divisor (GCD) or Highest Common Factor (HCF) - it is the largest positive integer that divides each of the integers with zero remainder

FAQ

What is the Greatest Common Factor of 100 and 645?

GCF of 100 and 645 is 5