In this C program, we will find the product of digits of a number using while loop. 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

#### Required Knowledge

**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> int main() { int num, temp; long productOfDigit = 1; printf("Enter a Number\n"); scanf("%d", &num); temp = num; while(num != 0){ productOfDigit *= num % 10; num = num/10; } printf("Product of digits = %ld", temp, productOfDigit); return 0; }Output

Enter a Number 2436 Product of digits = 144

Enter a Number 2222 Product of digits of 2436 = 16

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