To know a person by mobile phone number for free is usually possible only if there is a good reason for it. For example, you or your family call and threaten from unknown numbers or send messages with obscene or illegal content, etc. If you are driven by simple curiosity, the probability to find the owner of an unknown number is reduced to almost zero.
Use the standard methods of search a person by mobile phone number. You can contact the nearest police station or the da's office and write a statement about the incident, if you, for example, threatened, annoyed by the calls made against you or your relatives fraudulent acts with the unknown or hidden numbers on a mobile phone. The same can be done by contacting the nearest area office of your mobile operator. Your request will be reviewed by experts and after that they will deal with the problem.
If you want to know a person by mobile phone number for free without any special reasons, will make it much more difficult, and the result will largely depend on luck. For example, try to contact the salon of cellular communication of the operator who owns the number. Inform the office that want to put money into this account (minimum amount possible). Before completing this procedure you will be asked to verify the data. Try to say that I'm afraid to make mistakes and not believe the phone belongs to the right person. Then it all depends on loyalty of the employee. It can tell you the name and surname of the owner, although not obligated to disclose subscriber information.
The easiest way to know a person by mobile phone number – just call on him. However, to do it better with a different SIM card to avoid causing any suspicion that subscriber. Better suited for this landline phones, since even the attackers often can call from social institutions, work place, etc., and they are unlikely to think so they want "to expose". If you are calling from a cell, try recording a conversation. Even if people do not call his name, but will chat rude and violate your rights, this record will certainly help in his quest when applying to special government agencies.