Prime Factorization of 21

What is the Prime Factorization of 21?

Answer: Prime Factors of 21: 3, 7

Explanation of number 21 Prime Factorization

Prime Factorization of 21 it is expressing 21 as the product of prime factors. In other words it is finding which prime numbers should be multiplied together to make 21.

Since number 21 is a Composite number (not Prime) we can do its Prime Factorization.

To get a list of all Prime Factors of 21, we have to iteratively divide 21 by the smallest prime number possible until the result equals 1.

Here is the complete solution of finding Prime Factors of 21:

The smallest Prime Number which can divide 21 without a remainder is 3. So the first calculation step would look like:

21 ÷ 3 = 7

Now we repeat this action until the result equals 1:

7 ÷ 7 = 1

Now we have all the Prime Factors for number 21. It is: 3, 7

Prime Factor Tree of 21

We may also express the prime factorization of 21 as a Factor Tree:

Prime factors of 21 factorization tree of 21

Prime Factorization Table

NumberPrime Factors
2, 3
7
23
32
2, 5
11
22 × 3
13
2, 7
3, 5
24
17
2 × 32
19
22 × 5
3, 7
2, 11
23
23 × 3
52
2, 13
33
22 × 7
29
2, 3, 5
31
25
3, 11
2, 17
5, 7

About "Prime Factorization" Calculator

This calculator will perform a Prime Factorization of any given number and will show all its Prime Factors. For example, it can help you find out what is the Prime Factorization of 21? (The answer is: 3, 7). Pick the number for factorization (e.g. '21'). After that hit the 'Calculate' button.
Prime factors are the positive integers having only two factors - 1 and the number itself

FAQ

What is the Prime Factorization of 21?

Prime Factors of 21: 3, 7

How many prime factors does 21 have?

Number 21 has 2 Prime Factors