C Programming to read a number and find its armstrong

/* to read a number and find its armstrong */
#include<stdio.h>
#include<math.h>
#include<stdlib.h>
int main()
{
    int n,x,sum=0,num;
    printf("Enter number: ");
    scanf("%d",&n);
    num=n;
    while(n!=0)
    {
        x=n%10;
        sum+=(float)pow(x,3);
        n/=10;
    }
    if (sum==num)
        printf("%d is armstrong",num);
    else
        printf("%d is not armstrong",num);
    system("pause");
    return 0;
}