## Write a Python Program to Find Factorial of Number Using Recursion.

#### Write a Python Program to Find Factorial of Number Using Recursion.

Factorial Number

The factorial of a non-negative integer ( n ) is the product of all positive integers less than or equal to ( n ). It is denoted by ( n! ) and is defined as:
𝑛! = 𝑛×(𝑛−1)×(𝑛−2)×…×3×2×1
For example:
5! = 5×4×3×2×1 = 120
0!is defined to be 1.

Factorials are commonly used in mathematics, especially in combinatorics and probability, to count the number of ways a set of elements can be arranged or selected.

##### Program
```def recur_factorial(n):
if(n<=1):
return n
else:
return n*recur_factorial(n-1)

if __name__=="__main__":
num=int(input("Enter the number: "))
if(num<0):
print("Sorry, factorial does not exist for negative numbers")
elif(num==0):
print("The factorial of 0 is 1")
else:
print("The factorial of",num,"is",recur_factorial(num))

```

Output:

Enter the number: 5
The factorial of 5 is 120

Enter the number: 6
The factorial of 6 is 720