C Program – Check Whether the Input Number is a Neon Number - Digit Sum of Square

C Basics

Check Whether a Number is Neon

A neon number is defined as a number for which the sum of the digits of its square equals the number itself. For instance, 9 is a neon number because 9² = 81 and 8 + 1 = 9. This program reads an integer, computes its square, adds the digits of the square, and checks if this sum is equal to the original number.

#include <stdio.h>
int main() {
    int n, square, sum = 0, rem;
    printf("Enter an integer: ");
    scanf("%d", &n);
    square = n * n;               // Compute the square
    while (square != 0) {
        rem = square % 10;        // Extract the last digit
        sum += rem;               // Add it to the sum
        square /= 10;             // Remove the last digit
    }
    if (sum == n) {
        printf("%d is a neon number.\n", n);
    } else {
        printf("%d is not a neon number.\n", n);
    }
    return 0;
}
Enter an integer: 9
9 is a neon number.

After computing the square, the program extracts each digit of the squared value, adds it to sum, and then checks if this sum equals the original number. If they match, the number satisfies the neon property.


Comments

💬 Please keep your comment relevant and respectful. Avoid spamming, offensive language, or posting promotional/backlink content.
All comments are subject to moderation before being published.

Loading comments...

C Basics❯

  1. 1C Hello World Program
  2. 2C Program to Print Your Own Name
  3. 3C Program to Print an Integer Entered by the User
  4. 4C Program to Add Two Numbers
  5. 5C Program to Multiply Two Floating‑Point Numbers
  6. 6C Program to Print the ASCII Value of a Character
  7. 7C Program to Swap Two Numbers
  8. 8C Program to Calculate Fahrenheit to Celsius
  9. 9C Program to Find the Size of int, float, double and char
  10. 10C Program - Add Two Complex Numbers
  11. 11C Program - Find Simple Interest
  12. 12C Program - Find Compound Interest
  13. 13C Program - Area And Perimeter Of Rectangle
  14. 14C Program - Check Whether a Number is Positive, Negative, or Zero
  15. 15C Program - Check Whether Number is Even or Odd
  16. 16C Program - Check Whether a Character is Vowel or Consonant
  17. 17C Program - Find Largest Number Among Three Numbers
  18. 18C Program - Calculate Sum of Natural Numbers
  19. 19C Program - Print Alphabets From A to Z Using Loop
  20. 20C Program - Make a Simple Calculator
  21. 21C Program - Generate Multiplication Table
  22. 22C Program - Reverse a Number
  23. 23C Program - Check whether the input number is a Neon Number
  24. 24C Program - Find All Factors of a Natural Number