# Prime Factors of 21

Prime Factors of 21 are 3 and 7

#### How to find prime factors of a number

 1.   Prime Factorization of 21 by Division Method 2.   Prime Factorization of 21 by Factor Tree Method 3.   Definition of Prime Factors 4.   Frequently Asked Questions

#### Steps to find Prime Factors of 21 by Division Method

To find the primefactors of 21 using the division method, follow these steps:

• Step 1. Start dividing 21 by the smallest prime number, i.e., 2, 3, 5, and so on. Find the smallest prime factor of the number.
• Step 2. After finding the smallest prime factor of the number 21, which is 3. Divide 21 by 3 to obtain the quotient (7).
21 ÷ 3 = 7
• Step 3. Repeat step 1 with the obtained quotient (7).
7 ÷ 7 = 1

So, the prime factorization of 21 is, 21 = 3 x 7.

#### Steps to find Prime Factors of 21 by Factor Tree Method

We can follow the same procedure using the factor tree of 21 as shown below:

So, the prime factorization of 21 is, 21 = 3 x 7.

#### Introduction to Prime Factors?

In mathematics, prime numbers are defined as all those natural numbers greater than 1 that has only two divisors one being number 1 and the other being the number itself. When we express any number as the products of these prime numbers than these prime numbers become prime factors of that number. Eg- Prime Factors of 21 are 3 x 7.

#### Properties of Prime Factors

• Prime factors are the set of factors that are unique to the number given.
• 2 is the only even prime factor any number can have.
• Two prime factors are always coprime to each other.
• 1 is neither a prime number nor a composite number and also 1 is the factor of every given number. So, 1 is the factor of 21 but not a prime factor of 21.

• Which is the smallest prime factor of 21?

Smallest prime factor of 21 is 3.

• Is 21 a perfect square?

No 21 is not a perfect square.

• What is the prime factorization of 21?

Prime factorization of 21 is 3 x 7.

• What are the factors of 21?

Factors of 21 are 1 , 3 , 7 , 21.

• What is prime factorization of 21 in exponential form?

Prime factorization of 21 in exponential form is 3 x 7.

• Is 21 a prime number or a composite number?

21 is a composite number.

• Is 21 a prime number?

false, 21 is not a prime number.

• How to find prime factorization of 21 easily?

To find prime factorization of 21 easily you can refer to the steps given on this page step by step.

• Which is the largest prime factors of 21?

The largest prime factor of 21 is 7.