HeadersFooters collection: Returns a HeaderFooter object that represents the slide number in the lower-right corner of a slide, or the page number in the lower-right corner of a notes page or a page of a printed handout or outline. Read-only.
Slide or SlideRange object: Returns the slide number. Read-only Integer.
Remarks
The SlideNumber property of a Slide object is the actual number that appears in the lower-right corner of the slide when you display slide numbers. This number is determined by the number of the slide within the presentation (the SlideIndex property value) and the starting slide number for the presentation (the FirstSlideNumber property value). The slide number is always equal to the starting slide number + the slide index number – 1.