porting from a Precedent to an AT&T phone

[AllTheseAnswers]

I have a Samsung Precedent on ST, and it is apparently Sprint because it has no SIM card and the model number has a "C" in it. I was given, as an early Christmas present, an AT&T Nokia Lumia 520. I think I'm out of luck, but maybe not. Is there any way to use the 520 with my current phone number? Like, can I port my current phone number off the Precedent and onto a SIM card for use in the 520?