How to get my number off an iphone to sell?

I have verizon, and recently upgraded my iphone 4 to a new Droid phone. I want to sell my Iphone, so I factory reseted it, but it still says my number when I go t the contacts. It also still shows the verizon 3g at the top but obviously doesn't work when I try and go on safari. Is it ok if I sell it like this? Will it just go away when whoever buys it uses it?

Yeah it will go away.