//program to check a number is prime or not in C Language #include<stdio.h> #include<conio.h> void main() { int n,i,flag=0; clrscr(); printf("\nEnter a number: "); scanf("%d",&n); for(i=2;i<n;i++) { if((n%i)==0) { flag=1; } } if(flag==0) { printf("\n%d is a prime number.,",n); } else { ...