We should not allow to create projects with only-num names.
I think regexp should be:
Also we shouldn't provide users to open pages like above as project. only as page. If page doesn't exist - show error and button to available pages.
or we can provide pages with projects as /coprs/fas_name/page/page_num/ instead of /coprs/fas_name/page_num/ to separate projects and pages.
I agree with #0. The project name should start with non-digit character.
Since Adam have already implemented fix, reassigned ticket.