That sounds very similar to a problem I've had.
The problem appeared on a Kobo reader: not only were there arbitrary page numbers (following a set number of words rather than the layout chosen by the Kobo's owner), but those page numbers were literally on the text, as GraciousMe reported.
My ePub was created with Sigil (and this problem has not been reported yet on other ePub reading devices). Owner of Kobo said he's never seen this problem before (other ebooks were mostly purchased on the Kobo site).
Any chance either he or I can do something about it? Does that sound like a feature of Kobo, or something I can tell my ePub not to do? I'm really at a loss.