Unwanted call from this number.... when call back nothing but silence

Just began getting calls from 206:801-9344. Whois bothering me from Seattle?

I have received calls from this number every day for the last few days and when I answer there is silence and if I call the number back I either get a fast busy signal if I dial with the area code or a non-working number recording if I don't dial the area code (my phone is the same area code).