Python Program to Find Factorial of Number Using Recursion

In this program, you’ll learn to find the factorial of a number using recursive function.

To understand this example, you should have the knowledge of the following Python programming topics:

• Python if…else Statement
• Python Functions
• Python Recursion

The factorial of a number is the product of all the integers from 1 to that number.

For example, the factorial of 6 is 1*2*3*4*5*6 = 720. Factorial is not defined for negative numbers and the factorial of zero is one, 0! = 1.

Source Code

# Factorial of a number using recursion

def recur_factorial(n):
   if n == 1:
       return n
   else:
       return n*recur_factorial(n-1)

num = 7

# check if the number is negative
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

The factorial of 7 is 5040

Note: To find the factorial of another number, change the value of num.

Here, the number is stored in num. The number is passed to the recur_factorial() function to compute the factorial of the number.