# What is the Greatest Common Factor of 28 and 140?

Greatest common factor (GCF) of 28 and 140 is **28**.

GCF(28,140) = 28

We will now calculate the prime factors of **28 and 140**, than find the greatest common factor *(greatest common divisor (gcd))* of the numbers by matching the biggest common factor of 28 and 140.

## How to find the GCF of 28 and 140?

We will first find the prime factorization of 28 and 140. After we will calculate the factors of 28 and 140 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 = 2^{2} × 7^{1}

### Step-2: Prime Factorization of 140

Prime factors of 140 are 2, 5, 7. Prime factorization of **140** in exponential form is:

140 = 2^{2} × 5^{1} × 7^{1}

### 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 140

List of positive integer factors of 140 that divides 28 without a remainder.

1, 2, 4, 5, 7, 10, 14, 20, 28, 35, 70

#### Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 28 and 140. The biggest common factor number is the **GCF** number.

So the **greatest common factor 28 and 140** is **28**.

Also check out the Least Common Multiple of 28 and 140

#### Related Greatest Common Factors of 28

#### Related Greatest Common Factors of 140

- GCF of 140 and 144
- GCF of 140 and 145
- GCF of 140 and 146
- GCF of 140 and 147
- GCF of 140 and 148
- GCF of 140 and 149
- GCF of 140 and 150
- GCF of 140 and 151
- GCF of 140 and 152
- GCF of 140 and 153
- GCF of 140 and 154
- GCF of 140 and 155
- GCF of 140 and 156
- GCF of 140 and 157
- GCF of 140 and 158
- GCF of 140 and 159
- GCF of 140 and 160

## Recent Comments

The gcf of 28 and other number is 14 if the lcm is 140 find the missing number