Are you... sure you want to know?
Like at some point, after your standard 5 (vision, sound, touch, taste, & smell), those dimensions gotta start wrapping back around to where they started. And at that point they must have to go THROUGH your tissues to do it.
I am saying that one of them surely is an electrified butt-plug. So that's six, and after that... that's where shit REALLY starts to get freaky!
That depends (on whether they can make money or not by pretending that they are).