There is a viewPublicProfile URI and handler.
The template for this handler also exists.
The handler, however, only considers a profile “public” if the user has made public comments, and it is only exposed from those comments.
I think this functionality has been long forgotten.
If you removed the check from the handler regarding the comments, you could expose this for any user. If you as as a user wanted to discover your own id, it is is possible, although it is not simple. To do this, login and upload a profile image. The profile image will be named with your user id at the end.
allowed_html filter in config.inc.php.