What is the GCF of 21 and 105

"Greatest Common Factor" Calculator

What is the Greatest common Divisor of 21 and 105?

Answer: GCF of 21 and 105 is 21

(Twenty-one)

Finding GCF for 21 and 105 using all factors (divisors) listing

The first method to find GCF for numbers 21 and 105 is to list all factors for both numbers and pick the highest common one:

All factors of 21: 1, 3, 7, 21

All factors of 105: 1, 3, 5, 7, 15, 21, 35, 105

So the Greatest Common Factor for 21 and 105 is 21

Finding GCF for 21 and 105 by Prime Factorization

The second method to find GCF for numbers 21 and 105 is to list all Prime Factors for both numbers and multiply the common ones:

All Prime Factors of 21: 3, 7

All Prime Factors of 105: 3, 5, 7

As we can see there are Prime Factors common to both numbers: 3, 7

Now we need to multiply them to find GCF: 3 × 7 = 21

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 21 and 105? (The answer is: 21). Select the first number (e.g. '21') and the second number (e.g. '105'). 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

"Greatest Common Factor" Calculator

GCF Table

Number 1	Number 2	GCF
6	105	3
7	105	7
8	105	1
9	105	3
10	105	5
11	105	1
12	105	3
13	105	1
14	105	7
15	105	15
16	105	1
17	105	1
18	105	3
19	105	1
20	105	5
21	105	21
22	105	1
23	105	1
24	105	3
25	105	5
26	105	1
27	105	3
28	105	7
29	105	1
30	105	15
31	105	1
32	105	1
33	105	3
34	105	1
35	105	35

GCF for 21 and 105

"Greatest Common Factor" Calculator

What is the Greatest common Divisor of 21 and 105?

Finding GCF for 21 and 105 using all factors (divisors) listing

Finding GCF for 21 and 105 by Prime Factorization

See Also

About "Greatest Common Factor" Calculator

"Greatest Common Factor" Calculator

GCF Table

FAQ

What is the Greatest common Divisor of 21 and 105?

See Also

Number 1	Number 2	GCF
6	105	3
7	105	7
8	105	1
9	105	3
10	105	5
11	105	1
12	105	3
13	105	1
14	105	7
15	105	15
16	105	1
17	105	1
18	105	3
19	105	1
20	105	5
21	105	21
22	105	1
23	105	1
24	105	3
25	105	5
26	105	1
27	105	3
28	105	7
29	105	1
30	105	15
31	105	1
32	105	1
33	105	3
34	105	1
35	105	35

Number 1	Number 2	GCF
6	105	3
7	105	7
8	105	1
9	105	3
10	105	5
11	105	1
12	105	3
13	105	1
14	105	7
15	105	15
16	105	1
17	105	1
18	105	3
19	105	1
20	105	5
21	105	21
22	105	1
23	105	1
24	105	3
25	105	5
26	105	1
27	105	3
28	105	7
29	105	1
30	105	15
31	105	1
32	105	1
33	105	3
34	105	1
35	105	35

Number 1	Number 2	GCF
6	105	3
7	105	7
8	105	1
9	105	3
10	105	5
11	105	1
12	105	3
13	105	1
14	105	7
15	105	15
16	105	1
17	105	1
18	105	3
19	105	1
20	105	5
21	105	21
22	105	1
23	105	1
24	105	3
25	105	5
26	105	1
27	105	3
28	105	7
29	105	1
30	105	15
31	105	1
32	105	1
33	105	3
34	105	1
35	105	35