GCF for 28 and 70

What is the Greatest Common Factor of 28 and 70?

Answer: GCF of 28 and 70 is 14

(Fourteen)

Finding GCF for 28 and 70 using all factors (divisors) listing

The first method to find GCF for numbers 28 and 70 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 70: 1, 2, 5, 7, 10, 14, 35, 70

So the Greatest Common Factor for 28 and 70 is 14

Finding GCF for 28 and 70 by Prime Factorization

The second method to find GCF for numbers 28 and 70 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 70: 2, 5, 7

As we can see there are Prime Factors common to both numbers: 2, 7

Now we need to multiply them to find GCF: 2 Γ— 7 = 14

GCF Table

Number 1Number 2GCF
13701
1470
15705
16702
17701
18702
19701
2070
2170
22702
23701
24702
2570
26702
2770
2870
29701
3070
31701
32702
33701
34702
3570
3670
37701
38702
39701
4070
41701
4270

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 28 and 70? (The answer is: 14). Select the first number (e.g. '28') and the second number (e.g. '70'). 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 28 and 70?

GCF of 28 and 70 is 14