I had created "ubuntuuser", now it's gone (I erased the user) but his folder remains, and I can't remove it. rmdir ubuntuuser doesn't work (Permission denied)

sudo ... ( Directory not empty)

sudo rmdir ubuntuuser --ignore-fail-on-non-empty (nothing happens, no message but directory is not removed).

If I right-click on the folder (Nautilus), now the owner is 1003 - user #1003 (?)

Group: 1004 (?)

And the Folder access options are disabled.

So? How can I erase that folder?