This is an obvious scam with a "555" number. Caller ID simply says "Dist of Columbia".

Robo calls to my work phone. I do not answer, no message is left on voice mail. Other sites report that this is a lottery scam where, if you answer and talk to a person, they will tell you that you won a cash prize and ask for banking information to transfer the money to you.

This is the absolute worst kind of scam call designed to steal assets from vulnerable/gullible individuals.  Block this number if you can do so.