In this article, we are going to **write a Prime Number Program In C** **Using Recursion**.

To make this program, we will use the following concept given below.

If you do not know about these topics well, then you may not understand this program, so you should know about them in detail from the link given above.

Now without wasting time let’s start programming.

Page Contents

## C Program To Find Prime Number Using Recursion

### Algorithm

- Program Start
- Declare Variables
- Input A Number to check prime or not
- Calling Recursive Function
- Check conditions
- Check conditions and return result
- Recursive Function End
- Check Condition and Display Result
- Program End

### Program

```
//Prime Number Program In C Using Recursion
#include<stdio.h>
int PrimeorNot(int, int);
void main()
{
//variable declaration
int num, prime;
//input number
printf("Enter a positive number to check Prime or Not: ");
scanf("%d", &num);
//calling function
prime = PrimeorNot(num, num/2);
//checking condition and display result
if(prime == 1)
{
printf("%d is a prime number\n", num);
}
else
{
printf("%d is a not a prime number\n", num);
}
}
//recursive Function
int PrimeorNot(int n, int i)
{
if(i == 1)
return 1;
else
{
if(n%i == 0)
return 0;
else
PrimeorNot(n, i-1);
}
}
```

### Output

```
Enter a positive number to check Prime or Not: 11
11 is a prime number
```

## Conclusion

So friends, in this article, we have written **a Prime Number Program In C Using Recursion **

If you have difficulty to understand any program or have any doubts or questions, then tell me in the comment below.