Same thing here: They called my cell phone from this number. I answered, no one talked. I said "Hello?" again, and no one answers and the call immediately hangs up/ends. So I called the number back and it said the survey I was called for was over. So my guess is that it's a robot calling computer to call all the numbers it got a hold of (some telemarketing company or something), like mine, and they check for the number when they call it to see if a human voice answers or if it goes into a voicemail. Either way, I think its their sneaky sh*t way of detecting whether a phone number they have in their calling database is still valid so they know that when their next scam is ready, they can try your number and it will be likely that a person will answer if that number is still valid.
This number called and when I said "hello thank you for calling, how may I help you?" It's silent for 30 seconds or so & then they hang up. I refuse to call the number back because I'm sure it's scam (also from reading the rest of the comments) but it makes me wonder because say if they are recording our voice like that other scam that is going on?
Called requesting to verify my info;gave them my Phone #, home address, ssn and birthday. They asked for my bank account; I gave that to them and told em I'd give them my pin # too if I could have sex with their grandmother. They said ok, here's my info for all you fine people....(630) 111-1212; 123 Main Street, Illinois, 111-11-1212; and I was born Jan 1st, 1981. I bank with nearest bank, and my pin # is 1212