Who called from 2131775108

Rec'd call from this number and no one was there.  It isn't a number I recognize.

Missed call no message

I got a call from this number I answered it and said who's calling nobody answered then I said hello who's calling and nobody said anything there was no noise on the other side of the line. Then they hung up I don't know who they are.

they showed up on my caller id as "unknown name."  I did not answer, and no message was left.

Caller ID said CALIFORNIA. When I answered, no one responded and the line disconnected shortly after.