Who called from 2136290000

just got a call from this number has anyone figured out where it is coming from and if it is some sort of scam

When call came up blocked local police department tracked back trap results from phone carrier to Park 5th at the time.

Called, left 3x voicemails that were a half-second long electronic-like buzz.  Very annoying

Calls you, but hangs-up the moment you answer.  It seems like an automated system that is just verifying your number is real, so they can add them to some telemarketing lists to use later, or sell to other telemarketing scumbags.

today....this number called me three times....same thing....calls and when you answer there is no one on the line....