Who called from 6104797900

no message

Called number back and it does not ring or pick up.  It's like a dead line.

Number has been on my caller ID last several days. When I call it back, it rings a few times then "If you would like to make a call..."

This number has been calling me and when I answer there is nobody on the other end.  When I call the number back from a land line it automatically hangs up.

They always call then the line goes dead.
Attempts to call back lead to a busy signal or dropped call.

Happens about twice a week.
This is a private cell number