Number is Armstrong number or not

//C program to check whether a number is Armstrong number or not.
#include <stdio.h>

int main()
{
int x,sum=0,LN,num;

printf("Enter a number: ");
scanf("%d",&x);
num=x;
while(num>0){
    LN=num%10;
    sum+=(LN*LN*LN);
    num=num/10;
    }
if(sum==x)
    printf("%d is an Armstrong number.",x);
else
    printf("%d is not an Armstrong number.",x);

return 0;
}