GCF for 15 and 9

"Greatest Common Factor" Calculator

Greatest Common Factor of

and

What is the Greatest common Divisor of 15 and 9?

Answer: GCF of 15 and 9 is 3

(Three)

Finding GCF for 15 and 9 using all factors (divisors) listing

The first method to find GCF for numbers 15 and 9 is to list all factors for both numbers and pick the highest common one:

All factors of 15: 1, 3, 5, 15

All factors of 9: 1, 3, 9

So the Greatest Common Factor for 15 and 9 is 3

Finding GCF for 15 and 9 by Prime Factorization

The second method to find GCF for numbers 15 and 9 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 15: 3, 5

All Prime Factors of 9: 3, 3

As we can see there is only one Prime Factor common to both numbers. It is 3

So 3 is the Greatest Common Factor of 15 and 9

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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 Divisor of 15 and 9? (The answer is: 3). Select the first number (e.g. '15') and the second number (e.g. '9'). 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

"Greatest Common Factor" Calculator

Greatest Common Factor of

and

GCF Table

Number 1Number 2GCF
191
291
393
491
591
693
791
891
999
1091
1191
1293
1391
1491
1593
1691
1791
1899
1991
2091
2193
2291
2391
2493
2591
2691
2799
2891
2991
3093

FAQ

What is the Greatest common Divisor of 15 and 9?

GCF of 15 and 9 is 3

See Also