When I get a number I don't recognize, I reject the call, with a text message, instructing them to text me instead. This text always comes back as an invalid number, the sender was 112-161-1611. I don't even know what country that would be. The same message came back when rejecting calls from 571-392-3718, 728-726-5197, 979-245-2079, 728-727-1512, 201-285-1830, 312-878-9350, 312-147-0948, 773-570-8021, 360-215-7411, 312-149-0035, 720-549-7517, 206-519-6562, 720-506-3019, 206-519-6562, 718-684-9079, 443-252-8243, 718-684-9079, 305-602-9280, 720-685-6307, 515-758-4004, 843-710-9764, 215-465-2379, 360-633-9617, 773-358-7189, 805-408-8105, 360-633-9277
 Jul 23rd, 2015
When trying to call this number back, it tells you the number is no longer in service. To me, that is a nice big hint to block their number.
 Aug 28th, 2014
Scam. These people also call from a similar number, almost the same but the other ends in 3717 instead of 3718.
 Jun 12th, 2012
No message. Caller ID says Reston but this is a Herndon, VA number.
 Jun 04th, 2012
Selling some sort of call-in life alert service for seniors. "Press 5 to be removed".
 Jun 01st, 2012