If you pick up an unknown caller and there is no one answering, just keep hitting ##### and this is supposed to delete your number from their system. Don't know if it really works, but its worth a try. I get about 4-5 of these type calls daily even though I have registered with the do not call bureau.
Reverse phone lookup indicated this is not a valid number. Now it has got to be a valid number to be able to dial from, unless the phone company has clones that cannot be traced. I don't answer calls from unknown numbers but it has to be from my phone company, Verizon, otherwise how would my phone number be available.