# What is the Greatest Common Factor of 128 and 140?

Greatest common factor (GCF) of 128 and 140 is 4.

GCF(128,140) = 4

We will now calculate the prime factors of 128 and 140, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 128 and 140.

GCF Calculator and
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## How to find the GCF of 128 and 140?

We will first find the prime factorization of 128 and 140. After we will calculate the factors of 128 and 140 and find the biggest common factor number .

### Step-1: Prime Factorization of 128

Prime factors of 128 are 2. Prime factorization of 128 in exponential form is:

128 = 27

### Step-2: Prime Factorization of 140

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

140 = 22 × 51 × 71

### Step-3: Factors of 128

List of positive integer factors of 128 that divides 128 without a remainder.

1, 2, 4, 8, 16, 32, 64

### Step-4: Factors of 140

List of positive integer factors of 140 that divides 128 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 128 and 140. The biggest common factor number is the GCF number.
So the greatest common factor 128 and 140 is 4.

Also check out the Least Common Multiple of 128 and 140