I actually answered this time and although I didn't stay on the phone long enough to hear the whole spiel, it's some call center for Sprint (SUPPOSEDLY) trying to sell something. So, basically, a telemarketer.
I got a call from this number today at 1:03pm pacific time for the first time. I was on Google at the time, so I searched the number. I couldn't make out what they were saying, then they hung up. Called the number back, and heard some clicks, and numbers dialing. I am also a Sprint customer.