Who called from 7192993813

Hung up on voicemail.  I'm on the DNC list.

This call had the above number on top line then an additional number 862-236-1252 on the bottom line.  Called on 10/28/2015 at 10:00  AM

Called and just went to vm, no message and I don't know the number, called on 10/28/15.

Got a call on my cell phone from this number today. They disconnected when I answered.

Hangup after answering.  I estimate they are either trolling for legitimate telephone numbers or people of specific types as targets to exploit.  May also be attempting to identify times of day when a phone number is answered.