A number is said to be Armstrong or Narcissistic Number if it is equal to the sum of its own digits raised to the power of the number of digits in a given number. Armstrong Number Example: number 371 is Armstrong number because: 3 3 + 7 3 + 1 3 = 371. List of Armstrong Numbers: 1, 2, 3, 4, 5, 6, 7, 8, 9, 153, 370, 371, 407, 1634, 8208, 9474 ...