C Program to Find Prime Factor

Posted in C Tutorial

Updated on Oct 06, 2024

By Mari Selvan

👁️ 281 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of programming, understanding the prime factors of a number is a fundamental task. Prime factors are the prime numbers that multiply together to give the original number.

Checking for prime factors involves determining whether a given number is divisible by prime numbers.

In this tutorial, we will explore a C program designed to check the prime factors of a given number.

The program involves identifying and displaying the prime factors of the specified number.

📄 Example

Let's delve into the C code that accomplishes this task.

isPrimeFactor.c

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#include <stdio.h>

  // Function to check if a number is a prime factor
  int isPrimeFactor(int number, int divisor) {
    // Check if the divisor is a prime factor of the number
    return (number % divisor == 0);
  }
  
  // Function to display prime factors of a number
  void displayPrimeFactors(int number) {
    printf("Prime factors of %d are: ", number);
  
    // Iterate through numbers to find prime factors
    for (int i = 2; i <= number; ++i) {
      // Check if i is a prime factor and divides the number
      while (isPrimeFactor(number, i)) {
        printf("%d ", i);
        number /= i;
      }
    }
    printf("\n");
  }
  
  // Driver program
  int main() {
    // Replace this value with the number you want to find prime factors for
    int number = 56;
  
    // Call the function to display prime factors
    displayPrimeFactors(number);
  
    return 0;
  }

💻 Testing the Program

To test the program with different numbers, modify the value of number in the main program.

Output

Prime factors of 56 are: 2 2 2 7

Compile and run the program to display the prime factors of the specified number.

🧠 How the Program Works

The program defines a function isPrimeFactor that takes two integers, number and divisor, and returns 1 (true) if divisor is a prime factor of number, and 0 (false) otherwise.
The function displayPrimeFactors iterates through numbers to find prime factors of the given number and prints them.
Inside the main program, replace the value of number with the desired number you want to find prime factors for.
The program calls the displayPrimeFactors function to find and display prime factors.

🧐 Understanding the Concept of Odd Number

Before delving into the code, let's understand the concept of prime factors. Prime factors are prime numbers that multiply together to give the original number.