It's a scam. My phone instantly blocks them now. First time I ever got a call like this I answered it and just went along with it but didn't give them my information since I knew it was bull. It's always very loud in the back and they have a heavy accent.
I received a number from 202-011-1401 - saying I was randomly chosen to receive $7k from the Federal Grant Department. To be a S*** back at him, I wasted his time. His name was Silvester Smith - he gave me a number to call back to claim my $7k with a reference code. Obviously, I did not call back. Silvester called me back asking if I had called that number - I told him no because its a freaking scam and I called the sheriffs office. Once I said I had called the sheriffs office, he hung up. I blocked the number.