3 digit armstrong number in python

Overview

A number of n-digits can be defined as an Armstrong number if and only if the sum of its digits powered to n is equal to the number itself. For example, 1634 is an Armstrong number as 1634 = 1^4 +6^4 +3^4 + 4^4

Scope

• In this article, we will learn what an Armstrong number is.
• We will also learn various algorithms for identifying if a number is an Armstrong number or not, along with its implementation in Python.

What are Armstrong Numbers?

The Armstrong number in python is the number in which the sum of each digit powered to the total number of digits is the same as the given number. i.e. for a given number say 153, 1^3 + 5^3 + 3^3 is equal to 153. Take another example, say, 1634 = 1^4 +6^4 +3^4 + 4^4 is an Armstrong number. Any number in any number system exhibits this sum property, which will be called an Armstrong number.

Armstrong numbers are also called Narcissistic numbers. Armstrong numbers don’t have real-life applications. It is just another number puzzle.

Algorithm for checking if the given three-digit number is an Armstrong Number in Python

To find a 3-digit Armstrong number, we start by extracting each digit in the number, multiplying it thrice (to calculate its cube) and then adding all those cubes of digits.

Now, the sum will be compared with the given number. If the sum of cubes is the same as the actual number, then we call it an Armstrong number; otherwise, it is not an Armstrong number.

Step 1: Read number
Step 2: Declare a variable sum and initialize it to 0
Step 2: for each digit in the number, multiply it thrice and add it to the sum.
Step 3: check the sum if it is equal to the initial number
Step 4: If both are equal, then print it as an Armstrong number. Else, print it as not an Armstrong number.

Python Program for checking if the given three-digit number is an Armstrong Number

Code:

number = 153
temp = number
add_sum = 0
while temp != 0:
    k = temp % 10
    add_sum += k*k*k
    temp = temp//10
if add_sum == number:
    print('Given number is a three-digit Armstrong Number')
else:
    print('Given number is not an Armstrong Number')

Output:

Given number is a three-digit Armstrong Number

Algorithm for checking if the given n-digit number is an Armstrong Number in Python

To find if an n-digit number is an Armstrong number or not, we will first calculate the number of digits that is equal to n. Then we will extract each digit in the number and multiply it n times by itself (to calculate the nth power of it ) and add all those numbers to the sum variable. Now, we will check if the sum is equal to the given number or not. If both are equal, then we will print it as an Armstrong number or print it as not an Armstrong number.

Step 1: Take input
Step 2: Calculate the number of digits and store it as digits
Step 2: Declare a variable sum and initialize to 0
Step 2: for each digit in the number, multiply the same digit for digits times and then add it to the sum.
Step 3: Check if the sum is equal to the input number or not
Step 4: Print it as an Armstrong number if it is equal. Else print not an Armstrong number.

Python Program for checking if the given n-digit number is an Armstrong Number

Code:

number = 1634
digits = len(str(number))
temp = number
add_sum = 0
while temp != 0:
    # get the last digit in the number
    k = temp % 10
    # find k^digits
    add_sum += k**digits
    # floor division
    # which update number with second last digit as last digit
    temp = temp//10
if add_sum == number:
    print('Given number is an Armstrong Number')
else:
    print('Given number is not a Armstrong Number')

Output:

Given number is an Armstrong Number

Explanation:

14+64+34+44=16341^4+6^4+3^4+4^4 = 1634

As the sum of digits powered to the number of digits is equal to the number itself, the given number is an Armstrong number.

Conclusion

• We learned about what Armstrong numbers are.
• We also saw how to identify if a number is an Armstrong number or not in Python
• We also learned various algorithms and their implementation to check whether the given number is an Armstrong number.