This was a legit call that I was expecting from the Utah State Tax Commission. I had originally called a different number to contact them and this is the number they returned the call from. When I called it back I too got a message saying that this number had not been assigned. Don't know why or how they use this number to call out of.
I ended up calling the original number I used to contact the USTC right after they called from this number, and they verified that they were indeed the ones who had just tried to call me.
Number is legit, not spam. I know this something you almost never hear in today's bombardment by telemarketers.