# Count Number of Trailing Zeros in Factorial C Program

## C Program To Count Number of Trailing Zeroes in Factorial of Number

Here’s a C Program To Count the Number of Trailing Zeros in Factorial of a Number. While Calculating Factorial of an Integer, you may get a Long Number ending with Multiple Zeroes. This Code Finds the Total Number of Zeroes at the End of a Factorial of any Number.

#### Example For Trailing Zeros in Factorial of Number

**5! = 120**

Number of Trailing Zeros = 1

**50! = 30414093201713378043612608166064768844377641568960512000000000000**

It is also expressed as **3.0414093201713E+64**

Here, we have to consider Prime Factors of the Number of which the Factorial is being calculated. Remember, Trailing Zeros are always generated if the Number is a **Prime Factor of 5 and 2**.

**Also Read: C Program To Find Prime Numbers**

#### Method 1: C Program To Find Number of Trailing Zeros in Factorial of a Number using While Loop

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | #include<stdio.h> int main() { int num, count, total = 0; printf("Enter an Integer:\t"); scanf("%d", &num); count = 5; while((num/count) >= 1) { total = total + num/count; count = count * 5; } printf("Total Number of Trailing Zeroes: \t%d", total); printf("\n"); return 0; } |

**Also Read: C Program To Calculate Factorial of a Number using Loops**

#### Method 2: C Program To Count Number of Trailing Zeros in Factorial of an Integer using For Loop

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | #include<stdio.h> int main() { int num, count, total = 0; printf("Enter an Integer:\t"); scanf("%d", &num); for(count = 5; (num/count) >= 1; count = count*5) { total = total + num/count; } printf("Total Number of Trailing Zeroes: \t%d", total); printf("\n"); return 0; } |

**Also Read: Calculate Factorial of Number using Recursion in C Programming**

#### Output

If you have any doubts or compilation errors in this Code to Count Number of Trailing Zeros in a Factorial of any Integer, let us know about it in the Comment Section below.

Can we find zeros at the end of a float number that has decimal points in it?

I think it is possible! You need to take in float values!