FACT (Primitive Spread Function) returns the factorial of the specified number.

SYNTAX:

        FACT(value)

REMARKS:

The value argument must be a nonnegative number. The factorial is calculated as 1×2×3× . . . ×value. If you provide a number that is not an integer for the value argument, the decimal portion of the number is ignored. 

EXAMPLES:

FACT(B3)
FACT(10)=3628800