**Ans: **

In this tutorial you will learn writing program to print all possible prime factor of a given number in C.

Before moving on writing program lets know what is prime factor?

## What is Prime Factor?

It is a combination of two words “Prime” and “Factor”.

Prime means a number which can be only divisible by 1 and number itself.

**For Example:** 1, 2, 3, 5, etc.

And Factor is a part of a number which multiplication gives you the original number.

**For example:**

2*3 = 6

Here 2 and 3 are the prime factor of 6.

Prime factor is basically all factor of a number that should be prime number.

## How our program will behave?

The prime factor calculation program will take a number as a input and in result it will print all outputs with prime factors.

**For example** if you want to calculate the prime factor of a number 16 then you should give 16 as an input.

And After calculation program should return 2, 2, 2, 2 as an output.

## Program to find all Prime Factor of a given number in C

```
#include<stdio.h>
#include<conio.h>
#include<math.h>
void main() {
int i = 0, n;
printf("Please enter a number: ");
scanf("%d", & n);
printf("Prime factors of a given number \n");
while (n % 2 == 0) {
printf("%d, ", 2);
n = n / 2;
}
for (i = 3; i <= sqrt(n); i = i + 2) {
while (n % i == 0) {
printf("%d,", i);
n = n / i;
}
}
if (n > 2) {
printf("%d, ", n);
}
getch();
}
```

**Output 1:**

```
Please enter a number: 16
Prime factors of a given number
2, 2, 2, 2,
```

**Output 2:**

```
Please enter a number: 76
Prime factors of a given number
2, 2, 19,
```

## Explanation of the above program

- Above program is little bit logical but not hard to understand.
- We have 4 variables
,*i*,**j**,**n**.**temp**and**i**is initialized with 0.**temp** - First
will print 2 as a prime factor for each time when a number can be divide by 2.**while loop** - Now the next
will check if any odd number can divide a number.*for loop* - And last
is to print those number as a**if statement**which square root is less than 3.**prime factor**

I hope it has helped you to understand prime factor program using C Language.