numbers as file owners
 

In my linux (see left) I often see files and directories with ownerships settings as numbers.

There's a high variation in what those number can be and happen when I de-tar packages and stuff.

I suppose I can just chown -r all of them for simplicity's sake as they are off-putting. Anybody know why they occur?

In my linux (see left) I often see files and directories with ownerships settings as numbers.
Common for UID's that you don't have on the system. A quick way to check would be to do "getent passwd that_UID". Chowning them is the right way to go. Uncommon causes would be if you would have system auth reading problems (for instance wrong perms on /etc/passwd) or use app switches that doesn't translate UID's to usernames (like "ls -n").

cheers for the explanation unSpawn. BTW great work you do on the security front.

Sounds like whoever created the tar file is throwing in something like the --same-owner switch when creating the tar file.
The most common reason I've seen for numbers is when users are deleted.