C Program to Find Product of Digits of a Number

• Write a C program to find product of digits of a number using while loop.
• Wap in C to multiply the digits of a number.

Required Knowledge

• C printf and scanf functions
• While loop in C

To multiply digits of a number we have to remove one digit at a time, we can use ‘/’ division and ‘%’ modulus operator. Number%10 will give the least significant digit of the number, we will use it to get one digit of number at a time. To remove last least significant digit from number we will divide number by 10.

Product of digits of 2534 = 2 x 5 x 3 x 4 = 120

Algorithm to find product of digits of a number

• Get least significant digit of number (number%10) and multiply it to the product variable.
• Remove least significant digit form number (number = number/10).
• Repeat above two steps, till number is not equal to zero.

C program to find sum of all even numbers between 1 to N using for loop

#include <stdio.h>
#include <conio.h>  
   
int main() {  
    int num, temp;  
    long productOfDigit = 1;  
   
    /* 
     * Take a number as input from user
     */ 
    printf("Enter a Number\n");  
    scanf("%d", &num);  
    temp = num;
     
    while(num != 0){
        /* get the least significant digit(last digit) 
         of number and multiply it to productofDigit */
        productOfDigit *= num % 10;
        /* remove least significant digit(last digit)
         form number */
        num = num/10;
    } 
   
    printf("Product of digits of %d = %ld", temp, productOfDigit);  
   
    getch();
    return 0;  
}

Output

Enter a Number
2436
Product of digits of 2436 = 144

Enter a Number
2222
Product of digits of 2436 = 16