This number is a calling card number. I just got a call from this number (213-408-0236) and it was my girlfriend. I asked her about it and she said it was her calling card.
This number is from a calling card company used by people to fish for personal information. It might be used from someone you know, but anyone claiming to be from medicare or some other agency is lying through their teeth.
Hey I am based in Vancouver, B.C and receieved a call from this number. I answered it as its my business phone and i heard some people talking in the back and they hung up.