How to reference the page of a figure?

see figure~\ref{figure-xyz} on page~\pageref{figure-xyz}

Also see the varioref package which lets you write see figure~\vref{figure-xyz} which will automatically add the "on page NN" iff the figure is not on the current page.

Just use \pageref{}, so in your case:

see figure \ref{figure-xyz} on page \pageref{figure-xyz}