GCF for 20 and 690

What is the Greatest Common Factor of 20 and 690?

Answer: GCF of 20 and 690 is 10

(Ten)

Finding GCF for 20 and 690 using all factors (divisors) listing

The first method to find GCF for numbers 20 and 690 is to list all factors for both numbers and pick the highest common one:

All factors of 20: 1, 2, 4, 5, 10, 20

All factors of 690: 1, 2, 3, 5, 6, 10, 15, 23, 30, 46, 69, 115, 138, 230, 345, 690

So the Greatest Common Factor for 20 and 690 is 10

Finding GCF for 20 and 690 by Prime Factorization

The second method to find GCF for numbers 20 and 690 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 20: 2, 2, 5

All Prime Factors of 690: 2, 3, 5, 23

As we can see there are Prime Factors common to both numbers: 2, 5

Now we need to multiply them to find GCF: 2 × 5 = 10

GCF Table

Number 1Number 2GCF
56905
66906
76901
86902
96903
1069010
116901
126906
136901
146902
1569015
166902
176901
186906
196901
2069010
216903
226902
2369023
246906
256905
266902
276903
286902
296901
3069030
316901
326902
336903
346902

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 Factor of 20 and 690? (The answer is: 10). Select the first number (e.g. '20') and the second number (e.g. '690'). 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

FAQ

What is the Greatest Common Factor of 20 and 690?

GCF of 20 and 690 is 10