I have been getting repeated calls from this number wheen I lift the call and say hello no one answers

This number has called me 4 times since 8:30am and no one answers when I say hello.
Once I answered by holding the phone up to my speakers and that got the idiot man on the other side saying "hello hello" to me.
Then I got on and asked who he was and he hung up. W. T. F?!