There are some services which can provide such cell phone number information as the service career and phone line type for free. However, they charge for the identifying information such as the name and address of the phone owner. There are basically two reasons for this.
1. Data collecting. It takes time, money and human resources to find, organize and maintain a database of phone numbers.
2. No public mobile directory. A public cell phone directory does not currently exist due to various privacy concerns. Mobile carriers refused to cooperate in the past when such a directory was proposed.