C Program to Check Prime or Not

Check Prime or Not in C

To check whether the input number is a prime number or not a prime number in C programming, you have to ask to the user to enter a number and start checking for prime number. If number is divisible by 2 to one less than that number (i.e., n-1), then the number is not prime number, otherwise it will be prime number.

C Programming Code to Check Prime or Not

Following C program ask the user to enter a number to check whether it is a prime number or not, then display it on the screen:

/* C Program - Check Prime or Not */
		
#include<stdio.h>
#include<conio.h>
void main()
{
	clrscr();
	int num,i,count=0;
	printf("Enter a number:");
	scanf("%d",&num);
	for(i=2;i<num;i++)
	{
		if(num%i==0)
		{
			count++;
			break;
		}
	}
	if(count==0)
	{
		printf("This is a prime number");
	}
	else
	{
		printf("This is not a prime number");
	}
	getch();
}

When the above c program is compile and executed, it will produce the following result. Above C Programming Example Output (for prime number):

Above C Programming Example Output (for not prime number):

Same Program in Other Programming Language

You may also like same program in other programming languages:

• C++ Check Prime or Not
• Java Check Prime or Not
• Python Check Prime or Not

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