Who called from 3608336150

This number calls and never leaves a message.

Got a call from this number and did not answer as I know Noone from a Washington area code and I am in the caribbean

They called. Didn't leave a message. I blocked.

Relentless calls to my  cell phone from this number are very aggravating.  Assume sales call - will not buy anything from company that carpet bombs my cell phone number at all hours of the day when I am busy at work with my clients.  I think this call is from an investment broker.

Number in Washington.  Frontier Communications?  Don't know them or accounts with them.