It is possible that you get a phone call or a text message from an unknown number while you are in Turkey. The easiest way to learn who the number belongs to is to call a paid service. You can just call 11880 from your cell phone or desktop phone and ask for the number you want to learn.
It is not only the unknown numbers you can learn from this service. You can get information about the nearest bank branch, entertainment activities, case inquiry, call fro a plumber, learn zip codes, ask for the nearest florist, call for vehicle recovery service, call a locksmith, the nearest pharmacy on duty, hospitals and ambulance, and security departments.