What is a factorial symbol?

Answer 1

The symbol commonly used to denote factorial is the exclamation point ( ! ).

E.g.

1! = 1

2! = 2

3! = 6

4! = 24

5! = 120

x! = x*(x-1)*(x-2)*(x-3)*(x-4)* ... *3*2*1 , where x is an integer.