The numbers are indices to (in this case) string resources in Shell32.dll. They are language-specific. If you're using an English language version of Windows, you would see no difference if you deleted these entries. But if you were using a non-English version, the display names would revert from your native language to English. But on any language version, the default User folders always have English names in the file system. That's the 'Localized' in LocalizedResourceName!
Furthermore, If you rename one of these folders, say rename Documents to Bob, the entry in desktop.ini will change to:
[.ShellClassInfo]
LocalizedResourceName=Bob
But the actual folder name in the file system would remain unchanged (which can be verified by viewing the parent directory in a Command Prompt or PowerShell).
If you search onlne, you can find freeware Resource viewers/hackers which would allow you to explore the contents of dll files (explore a copy, not the original!!!)
Keith