Remove page

Is there a way to have page numbering removed by default, rather than going to format >page>header…then footer?

The current default page style comes with the template of the spreadsheet document. Use the stylist >Format>Manage Styles (F11) to change the header style/content or to switch off the header completely.
If you want this to be the default also for your new spreadsheet documents, save a prepared document as template (.ots) and define it as your standard.
My personal default template for spreadsheet documents, e.g, has no Header or Footer in the page style (and a monotype font for the default cell style: old-fashioned.)

perfect, thanks