Python | math.factorial() function (original) (raw)

Last Updated : 16 Feb, 2023

In Python, math module contains a number of mathematical operations, which can be performed with ease using the module. math.factorial() function returns the factorial of desired number.

Syntax: math.factorial(x)

Parameter: x: This is a numeric expression. Returns: factorial of desired number. Time Complexity: O(n) where n is the input number. Auxiliary space: O(1)

Code #1:

Python3 `

Python code to demonstrate the working of factorial()

importing "math" for mathematical operations

import math

x = 5

returning the factorial

print ("The factorial of 5 is : ", end ="") print (math.factorial(x))

`

Output:

The factorial of 5 is : 120

Code #2:

Python3 `

Python code to demonstrate the working of factorial()

importing "math" for mathematical operations

import math

x = 5 y = 15 z = 8

returning the factorial

print ("The factorial of 5 is : ", math.factorial(x)) print ("The factorial of 15 is : ", math.factorial(y)) print ("The factorial of 8 is : ", math.factorial(z))

`

Output:

The factorial of 5 is : 120 The factorial of 15 is : 1307674368000 The factorial of 8 is : 40320

Code #3: Throws ValueError if x is not integer

Python3 `

Python code to demonstrate the working of factorial()

importing "math" for mathematical operations

import math

when x is not integer

print ("math.factorial(13.7) : ", math.factorial(13.7))

`

Output:

ValueError: factorial() only accepts integral values