I tried that number on searchbug, it says no match found, which means it is probably an inside line and you would need to know the trunk number, and obviously you don't know that without knowing the company. Sorry. My bet is it is a company that you already have some dealing with (credit card, internet server, whatever) trying to get you to upgrade to something better. Many will hang up after two rings so they don't get your answering machine (if you had one).