**What is a Prime Number ? **

Prime number is a natural number greater than 1 that has no positive divisors other than 1 and the number itself

In other words, we can say prime numbers don’t have any factor other than 1 and itself.

**For Example** – 2, 3, 5, 7, 11, 13, 17, 19, 23, 29 are Prime Numbers.

### Examples of Prime Numbers

**Question 1**

Which of the following is a prime number?

3, 6, 9

**Explanation**

Factors of 6 are 2 x 3 x 1

Factors of 3 are 3 x 1

Factors of 9 are 3 x 3 x 1

Here, Factors of 3 are 3 and 1

3 is not divisible by any other number, other than 1 and itself

Therefore, 3 is a prime number.

**Question 2**

Which of the following is a prime number?

10, 15, 5

**Explanation**

Factors of 10 are 2 x 5 x 1

Factors of 5 are 5 x 1

Factors of 15 are 3 x 5 x 1

Here, Factors of 5 are 5 and 1

5 is not divisible by any other number, other than 1 and itself

Therefore, 5 is prime number.

**Question 3**

Which of the following is a prime number?

26, 13, 30

**Explanation**

Factors of 26 are 2 x 13 x 1

Factors of 13 are 13 x 1

Factors of 30 are 3 x 5 x 2 x 1

Here, Factors of 13 are 13 and 1

13 is not divisible by any other number, other than 1 and itself

Therefore, 13 is a prime number.

**Question 4**

Which of the following is a prime number?

34, 17, 51

**Explanation**

Factors of 34 are 2 x 17 x 1

Factors of 17 are 17 x 1

Factors of 51 are 3 x 17 x 1

Here, Factors of 17 are 17 and 1

17 is not divisible by any other number, other than 1 and itself

Therefore, 17 is prime number.

**Question 5**

Which of the following is a prime number?

19, 38, 57

**Explanation**

Factors of 38 are 2 x 19 x 1

Factors of 19 are 19 x 1

Factors of 57 are 3 x 19 x 1

Here, Factors of 19 are 19 and 1

19 is not divisible by any other number, other than 1 and itself

Therefore, 19 is prime number.