# C Program find whether a Number is Prime Or Composite using Recursion

## C Program find whether a Number is Prime Or Composite using Recursion

**Prime Number:**A number that is only divisible by 1 and itself.**Composite Number:**A number that is not a prime number.

Note:1 is neither prime nor composite.

Below is a program to find whether the user input number is a prime number or a composite number using recursion.

```
#include<stdio.h>
// declaring the recursive function
int isPrime(int, int);
int main()
{
printf("\n\n\t\tEduguru - Recursion program example\n\n\n");
int num, prime;
printf("Enter a positive number to check if Prime: ");
scanf("%d", &num);
prime = isPrime(num, num/2);
if(prime == 1)
{
printf("\n\n%d is a prime number\n\n", num);
}
else
{
printf("\n\n%d is a Composite number\n\n", num);
}
printf("\n\n\t\t\tCoding is Fun !\n\n\n");
return 0;
}
// function definition
int isPrime(int n, int i)
{
if(i == 1)
return 1; // return statement terminates the recursive funtion
else
{
if(n%i == 0)
return 0;
else
isPrime(n, i-1); // recursive call not using return statement
}
}
```

Another reference program of prime number