Is 11 a prime number?

11 is a prime number and on the prime factorization of 11, we obtain only 1 and 11 as the factor of 11. And, also it contains exactly two factors, which are 1 and 11, where it is known as the prime number.

To conclude that 11 is a prime number or not, you need to find out its factors. Here, the factors of 11 are 1 and 11, then it is said to be a prime number. And, there are some methods to find out whether a particular number is prime or composite. They are listed below:

• Counting Divisors Method

• Divisibility Test Method

• Prime Number Chart

• Prime Factorization
   

In the counting divisors method, we list the divisors of the given number and check if the number, to be considered prime, satisfies the two conditions.

The counting divisors method for 11:

Divisors of 11 = 1, 11.

Number of divisors = 2

The number 11 is a prime number.
 

In this method, the prime number only has two divisors, which are one and the number itself. Hence, there is no divisibility test for the number 11 other than checking if it is divisible by 1 and 11.
 

List the prime number chart up to 20.

The prime numbers from 1 to 15 are 2, 3, 5, 7, 11, 13, 17, 19. By keeping a note of the prime number chart, we can conclude that 11 is a prime number.
 

Prime factorization is only applicable to non-prime numbers/composite numbers. As long as 11 has no other factor than 1 and 11, it has no option to be factored into smaller prime numbers.
 

• Prime Number: A number that can be divided by itself and 1 is called a prime number.

• Composite Number: A number that can be prime factorized further. It has factors more than two factors, 1 and itself.

• Prime Factorization: Breaking down a number into smaller factors is said to be a prime factorization.