@echo off
:code
set /p "numero=Numero : "
if not defined numero (goto:code)
set /a "factorial=1"
for /l %%_ in (1 1 %numero%) do (
set /a factorial=factorial * %%_
)
echo.Factorial : %factorial%
pause>nul
exit /b 0

Numero : 4
Factorial : 24