It's an auto-dialer. It hangs up because, once you're connected, it can't find someone at its end for you to talk to.
It then puts you in the queue to call back later.
and then it calls you back and can't find someone at its end for you to talk to so it hangs up.
It then puts you in the queue to call back later.
and then it calls you back and can't find someone at its end for you to talk to so it hangs up.
Someone at this number calls every couple of days and asks for my wife by name. He doesn't say he is with any business or organization. He doesn't make any threats. He doesn't leave any message. It is annoying, somewhat unsettling, and very unwelcome.