GCF for 30 and 66

What is the Greatest common Divisor of 30 and 66?

Answer: GCF of 30 and 66 is 6

(Six)

Finding GCF for 30 and 66 using all factors (divisors) listing

The first method to find GCF for numbers 30 and 66 is to list all factors for both numbers and pick the highest common one:

All factors of 30: 1, 2, 3, 5, 6, 10, 15, 30

All factors of 66: 1, 2, 3, 6, 11, 22, 33, 66

So the Greatest Common Factor for 30 and 66 is 6

Finding GCF for 30 and 66 by Prime Factorization

The second method to find GCF for numbers 30 and 66 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 30: 2, 3, 5

All Prime Factors of 66: 2, 3, 11

As we can see there are Prime Factors common to both numbers: 2, 3

Now we need to multiply them to find GCF: 2 × 3 = 6

See Also

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 Divisor of 30 and 66? (The answer is: 6). Select the first number (e.g. '30') and the second number (e.g. '66'). 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

GCF Table

Number 1Number 2GCF
15663
16662
17661
1866
19661
20662
21663
2266
23661
2466
25661
26662
27663
28662
29661
3066
31661
3266
336633
34662
35661
3666
37661
38662
39663
40662
41661
4266
43661
4466

FAQ

What is the Greatest common Divisor of 30 and 66?

GCF of 30 and 66 is 6