Assume that one of the pages in a report is set up in a landscape layout, while all the other pages are in a portrait layout.
When all the pages are combined into a single report, the page number that should be at the bottom of the landscape page will not be printed at the bottom-center, but on the bottom-right (the footer of a page printed in a landscape layout).

Type the page number in a cell of the sheet, not in the Header/Footer of Page Setup dialog box.
Example: This balance Sheet has many columns, and is printed in a landscape layout while all other pages are printed in a portrait mode.

1. Select column A.
2. Right-click, and select Insert from the shortcut menu.
3. In cell A3, type the number of the page in the report (in this example, 5).
4. Select the range A3:A30, click Home -> then click on three commands:
Merge & Center (in Alignment Group).
Middle Align (in Alignment Group).
Orientation (in Alignment Group) -> Rotate Text Down.
5. Update the print area to include range A3:A30, select range A3:G30, select Page layout -> Print Area (in Page Setup Group) -> Set Print Area.