When I answered, I heard what sounded like a timed "beep" as sometimes happens when a fax machine calls a voice number. I believe it to be a recording device, possibly similar to the "do not call" scam.

If you get a call from this number and you say "hello", please be very careful what you say. Do not have a conversation with it. Scammers are the lowest of the absolute low and they don't deserve your attention. HANG UP!

One reason not to say "yes?!" when you answer the phone, it's a very bad idea.