WordPress.org

It is not possible to have a page slug (the page's name in the URL) that is a number. For example this will not work: yoursite.com/about/2/. That URL conflicts with paged content feature where you can posts and pages with multiple pages of content by adding <!--nextpage--> within your content.

This plugin allows you to have Pages with numbers as stubs by giving up the ability to have paged content pages which isn't a big deal as most people don't use paged content pages anyway.