Answer #include<stdio.h>
int main(){
    int num,i,count=0;
    printf("Enter a number: ");
    scanf("%d",&num);
    for(i=2;i<=num/2;i++){
        if(num%i==0){
         count++;
            break;
        }
    }
   if(count==0 && num!= 1)
        printf("%d is a prime number",num);
   else
      printf("%d is not a prime number",num);
   return 0;
}Sample output:
Enter a number: 5
5 is a prime number 
+ ExplanationNot ModeratedDefinition of prime number:
A natural number greater than one has not any other divisors except 1 and itself. In other word we can say which has only two divisors 1 and number itself. For example: 5
Their divisors are 1 and 5.Note: 2 is only even prime number.Logic for prime number in c
We will take a loop and divide number from 2 to number/2. If the number is not divisible by any of the numbers then we will print it as prime number.