Let a friend call that number and make him sound important!
Call and ask maybe?
When you get around your friends call that number and see who's phone rings
call them up and ask, is this Larry?
You call them pretending to be telemarketer or something and ask for their name. Or ask "is this Mark?" And they'll maybe respond. No this is mr. X XD
this requires a court order :D wireless companies don't publish this information to private citizens. also, disposable wireless accounts and anonymous making this futile. if someone is harassing you please call the police before this escalates :( good luck!
It is possible! Whom are you seeking???
So ignore it and go on with your life!!!