Several ways to track a cell phone with the number include installing the Android application Plan B, using Apple's Find My iPhone application or calling the service provider. Even if a device recovery application is not installed on the lost phone, the previous methods find the lost phone.
If the lost phone has an Android operating system, the owner can download the Plan B application on his computer. The application is available on the Google Play website. Once it is installed, it downloads to the missing phone and sends the owner tracking information. After installation, the lost phone's owner can also text the phone the phrase "locate" from another phone to get a text with the tracking information.
If the lost phone is an iPhone, the owner can use the Find My iPhone application to track the phone and have it make a loud noise to pinpoint it when nearby. If the lost phone does not have the pre-installed application, the owner can find a different iDevice, install Find My iPhone on it, and log in with his Apple ID. The application shows a map with the location of the phone on it.
Tracking methods only work if the phone's battery is alive. The only other option is to call the service provider who may be able to track the phone for a fee.