The sum of the cube of individual digits of a number is equal to the number itself is called Armstrong number.
#include<iostream.h> #include<conio.h> void main() { clrscr(); int a,n,rev=0,x; cout << "enter the number" << endl; cin >>n; x=n; while(n>0) { a=n%10; rev=rev+a*a*a; n=n/10; } cout << "cube and sum of the digits=" << rev << endl; if(rev==x) { cout << "Armstrong" << endl; } else { cout << "Not Armstrong" << endl; } getch(); } Output: enter the number 371 cube and sum of the digits=371 Armstrong