User blog comment:SabrinaCarpenterLove/My Theory About Random Wikia Contributors/@comment-8-20160224190544

The numbers are IP addresses. They are used to identify edits if the person is not logged in.

IPs actually show more information than a username. If you can see an IP you can look-up the persons general area (like, their city or region) and what Internet Provider they use.

Admins can allow non-logged in users or not, depending on what they prefer, although wikis on topics that children are likely to use are always logged-in only

I hope that helps explain