# Coding interview question: Determine if number is an Armstrong number

## Problem statement

In this article we will be discussing another (see the previous article counting triples with a given sum) of the most common coding interview questions. The problem statement is really simple and goes as follows:

Given an positive integer N determine if it is an Armstrong number?
A number $x_1x_2…x_n$ (1 \leq x_i \leq 9 $is a digit ) of length$n$is an Armstrong number if the following is true:$x_nx_{n-1}…x_2x_1 = pow(x_1,n) + pow(x_2,n) + … pow(x_n,n)$In other words if raising all digits to power$n$and sum all them up you obtain the original number, then$N\$ is an Armstrong number.