Thanks for your post. Page numbers are added or deleted through "Header & Footer" tool in Acrobat.
Please navigate to Tools pane & choose Edit PDF tool. You will get the option of "Header & Footer", select the "Remove" option to delete the complete header & footer or you can choose the Update option to make changes in the Header & Footer.
If you will choose the Update option, Header & Footer dialogue box will come up on the screen, clear out the page number script ( Ex. : <<1>> ) & click on OK to confirm the changes.