Q: Does erase all settings and content remove phone number

This is probably a silly question, but does erase all settings and content mean that the phone is no longer assigned to a specific phone number? We bought my son a refurbished iPhone 5C and got it activated yesterday. He played with it for awhile before restoring a backup from his iPad, and now his games on his iPad and iPhone are not connected. From what I've read, it sounds like I need to erase the phone and restore from the iPad before doing anything else with the phone, but I want to make sure that erasing the phone won't mean having to re-activate it with Verizon?