Kotlin Program:

Example:

import java.util.Scanner
fun main(args: Array<String>) {
    
  val userInput = Scanner(System.`in`)
  print("Enter your number : ")
  var num:Int = userInput.nextInt()
  var digit:Int
  var sum:Int = 0
  var num2:Int = num
  while(num!=0) {
    digit=num%10
    sum= sum + digit*digit*digit
    num/=10
  }

  if(num2==sum)println("Armstrong Number")
  else println("Not a Armstrong Number")

}

Output:

  Enter Your number : 407
  Armstrong Number

You must know first,

Armstrong Number : if a number & cube of every single digit of the number are equal than the number is an Armstrong number

Example :

Number: 407 & cube of every single digit = 407. so it's an Armstrong Number
(4*4*4)+(0*0*0)+(7*7*7) = 64+0+343 = 407

//Save the original number
  num2=num

//find every single digit & add the cube of it
  while(num!=0) {
  digit=num%10
  sum=sum + digit*digit*digit
  num/=10
}

//check for the Armstrong
if(num2==sum)