# What is the Greatest Common Factor of 28 and 70?

Greatest common factor (GCF) of 28 and 70 is 14.

GCF(28,70) = 14

We will now calculate the prime factors of 28 and 70, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 28 and 70.

GCF Calculator and
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## How to find the GCF of 28 and 70?

We will first find the prime factorization of 28 and 70. After we will calculate the factors of 28 and 70 and find the biggest common factor number .

### Step-1: Prime Factorization of 28

Prime factors of 28 are 2, 7. Prime factorization of 28 in exponential form is:

28 = 22 × 71

### Step-2: Prime Factorization of 70

Prime factors of 70 are 2, 5, 7. Prime factorization of 70 in exponential form is:

70 = 21 × 51 × 71

### Step-3: Factors of 28

List of positive integer factors of 28 that divides 28 without a remainder.

1, 2, 4, 7, 14

### Step-4: Factors of 70

List of positive integer factors of 70 that divides 28 without a remainder.

1, 2, 5, 7, 10, 14, 35

#### Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 28 and 70. The biggest common factor number is the GCF number.
So the greatest common factor 28 and 70 is 14.

Also check out the Least Common Multiple of 28 and 70

#### Related Greatest Common Factors of 70

##### Recent Comments
Gabriela R. Angelez 2020-10-04 18:50:57

Amazing! My kids practice math using this website now. They're in 6th grade and now have a practice for them! I'm very proud.

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