whose phone number
If you are talking about the owner of the number, you can find them on reverse phone look up service providers like http://www.getphonecaller.com/ They are free of charge so you can use them anytime.
To find out whose phone number is calling, one can do a reverse phone number search. To do a search online visit http://www.whitepages.com.
If you want to find out whose phone number belongs to you better check this out http://tracecellphonenumberowner.com/