Numbering horizontal page - writer

Libreoffice PL, Ubuntu 14.04 PL.

I need to add site number on horizontal page on left or right site of page. The number should also be inverted.

Can anyone help?

What does “inverted” mean in this context, upside-down, flipped vertically, flipped horizontally? If you can edit the question to include a mockup that may help.

One way:
Click inside the frame
Menu/Insert/Fields/Page number
Select the field
Menu/Format/Character - Position - Rotate: 90 degrees