GCF for 28 and 63

What is the Greatest common Divisor of 28 and 63?

Answer: GCF of 28 and 63 is 7

(Seven)

Finding GCF for 28 and 63 using all factors (divisors) listing

The first method to find GCF for numbers 28 and 63 is to list all factors for both numbers and pick the highest common one:

All factors of 28: 1, 2, 4, 7, 14, 28

All factors of 63: 1, 3, 7, 9, 21, 63

So the Greatest Common Factor for 28 and 63 is 7

Finding GCF for 28 and 63 by Prime Factorization

The second method to find GCF for numbers 28 and 63 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 28: 2, 2, 7

All Prime Factors of 63: 3, 3, 7

As we can see there is only one Prime Factor common to both numbers. It is 7

So 7 is the Greatest Common Factor of 28 and 63

See Also

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 28 and 63? (The answer is: 7). Select the first number (e.g. '28') and the second number (e.g. '63'). 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

GCF Table

Number 1Number 2GCF
13631
1463
1563
1663
17631
1863
19631
20631
2163
22631
23631
2463
25631
26631
2763
2863
29631
30633
31631
32631
33633
34631
3563
3663
37631
38631
39633
4063
41631
4263

FAQ

What is the Greatest common Divisor of 28 and 63?

GCF of 28 and 63 is 7