#include<stdio.h>
#include<conio.h>
int main()
{
int number, i, flag=0;
clrscr();
printf("Enter integer number: ");
scanf("%d", &number);
for(i=2;i<=number/2; i++)
{
if(number%i==0)
{
flag = 1;
break;
}
}
if(flag==0 && number>=2)
{
printf("%d is PRIME.", number);
}
else
{
printf("%d is NOT PRIME.", number);
}
getch();
return(0);
}
Output
Run 1:
-----------
Enter integer number: 13 ↲
13 is PRIME.
Run 2:
-----------
Enter integer number: 16 ↲
16 is NOT PRIME.
Run 3:
-----------
Enter integer number: 1 ↲
1 is NOT PRIME.
Run 4:
-----------
Enter integer number: 2 ↲
2 is PRIME.