Using the Excel FACT Function

Summary
The Excel FACT function is used to return the factorial of a number. The factorial of a number is simply the product of the number and all those below it. For example, =FACT(4) is the same as 4 x 3 x 2 x 1 and both return 24.Syntax
=FACT (number)Syntax Breakdown
numberThe number argument is required in the FACT function. This is the number for which you want to find the factorial. Number must be non-negative. If it is not an integer, it will be truncated.
Usage Notes
The FACT function returns the factorial of a given non-negative number. The function returns the #NUM! error if a negative number is entered.