# What is the Greatest Common Factor of 57 and 66?

Greatest common factor (GCF) of 57 and 66 is 3.

GCF(57,66) = 3

We will now calculate the prime factors of 57 and 66, than find the greatest common factor (greatest common divisor (gcd)) of the numbers by matching the biggest common factor of 57 and 66.

GCF Calculator and
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## How to find the GCF of 57 and 66?

We will first find the prime factorization of 57 and 66. After we will calculate the factors of 57 and 66 and find the biggest common factor number .

### Step-1: Prime Factorization of 57

Prime factors of 57 are 3, 19. Prime factorization of 57 in exponential form is:

57 = 31 × 191

### Step-2: Prime Factorization of 66

Prime factors of 66 are 2, 3, 11. Prime factorization of 66 in exponential form is:

66 = 21 × 31 × 111

### Step-3: Factors of 57

List of positive integer factors of 57 that divides 57 without a remainder.

1, 3, 19

### Step-4: Factors of 66

List of positive integer factors of 66 that divides 57 without a remainder.

1, 2, 3, 6, 11, 22, 33

#### Final Step: Biggest Common Factor Number

We found the factors and prime factorization of 57 and 66. The biggest common factor number is the GCF number.
So the greatest common factor 57 and 66 is 3.

Also check out the Least Common Multiple of 57 and 66