Armstrong Number in Java
In this section, we will discuss what is Armstrong number and also create Java programs to check if the given number is an Armstrong number or not. The Armstrong number program frequently asked in Java coding interviews and academics.
Armstrong Number
An Armstrong number is a positive m-digit number that is equal to the sum of the mth powers of their digits. It is also known as pluperfect, or Plus Perfect, or Narcissistic number. It is an OEIS sequence A005188. Let’s understand it through an example.
Armstrong Number Example
1: 11 = 1
2: 21 = 2
3: 31 = 3
153: 13 + 53 + 33 = 1 + 125+ 27 = 153
125: 13 + 23 + 53 = 1 + 8 + 125 = 134 (Not an Armstrong Number)
1634: 14 + 64 + 34 + 44 = 1 + 1296 + 81 + 256 = 1643
Similarly, we can check other number also.
The first few Armstrong numbers between 0 to 999 are 1, 2, 3, 4, 5, 6, 7, 8, 9, 153, 370, 371, 407. Some other Armstrong numbers are 1634, 8208, 9474, 54748, 92727, 93084, 548834, 1741725, 4210818, 9800817, 9926315, 24678050, 24678051, 88593477, 146511208, 472335975, 534494836, 912985153, 4679307774, 32164049650, 32164049651.
Note that there is no two-digit Armstrong number.
Armstrong Number Java Program
The following Java program prints all the Armstrong numbers up to the specified limit.
ArmstrongNumberExample1.java
Output:
Enter the limit: 999 Armstrong Number up to 999 are: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 153, 370, 371, 407
Let’s create another Java program that checks if the given number is an Armstrong number or not.
ArmstrongNumberExample2.java
Output 1:
Enter the number: 2 Armstrong
Output 2:
Enter the number: 1675 Not Armstrong