# Python Program to Find Factorial of a Number

In this tutorial, we will discuss python program to find factorial of a number.

Before going to the program first, let us understand what is a *Factorial Number.*

**Factorial Number:**

- The factorial of a non-negative integer $n$ is the product of all positive integers less than or equal to $n$.
- For example, the factorial of 5 (denoted as 5!) is 120.

**Related: **Python Program to Find Perfect Number

#### Program code for finding factorial of a number in Python

# Factorial Program in Python def factorial(num): if num == 0 or num == 1: return 1 else: return num * factorial(num - 1) number = int(input("Enter a number: ")) print(f"The factorial of {number} is {factorial(number)}.")

#### Explanation

**Function Definition**: The`factorial`

function takes an integer`num`

as input and returns the factorial of the number.**Base Case**: If the number is 0 or 1, the function returns 1.**Recursive Case**: For any other number, the function recursively calls itself with the number decremented by 1.**Main Program**: The program prompts the user to enter a number and then calculates the factorial using the`factorial`

function.

#### Output

- When you run the above program, it will prompt you to enter a number.
- After entering the number, it will calculate the factorial of the number and print the result.

#### Conclusion

- In this tutorial, we learned how to calculate the factorial of a given number using a Python program.
- Understanding this concept is essential for solving various mathematical problems and competitive programming challenges.
- Practice this example to enhance your programming skills and understanding of factorials.