Here we will write a code in C language to check whether the entered number is a prime number or not.

**What is a Prime number?**

A natural number will be called a prime number if it is only divisible by 1 and itself. For example, 3 is a prime number because it is only divisible by 1 and itself.

**Steps**

- First, we ask the user to enter a number
- Then we create a loop from 2 to half of that number.
- Inside the loop using the if statement we will check whether the entered number is divisible by any of number between 2 to half of the entered number.
- If the number is divisible by any of number between 2 to half of the entered number, we will break the loop and print the statement that the entered number is not a prime number.

**Statements used**

- for loop
- break statement
- % (modules)
- if…..else

**C Program**

#include<stdio.h> #include<conio.h> void main() { int num, i; clrscr(); printf("Enter a number:"); scanf("%d",&num); if(num==1 ||num==2) printf("It is a Prime Number"); else{ for(i =2;i<=num/2;i++) { if(num%i==0) //check whether num is divisible by i or not { printf("It is not a Prime Number"); break; } else if(i==num/2) printf("It is a prime number "); } } getch(); }

**Output:**

Enter a number:49 It is not a Prime Number

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