I also had several missed calls from this number. Impossible to ring back, Vodafone message "Your call could not be connected" I suspect it is from a company about Investment Opportunities as I have had many calls from many obscure numbers after registering interest on a website about Stock Market Investment.

I had a missed call from this number, when I called back it said that Optus advises that his number is incomplete or incorrect.

I had a call from this number. There was some silence then a male voice said hello, I sail yes hello and he hung straight up. When I called back is said this number is not connected.

I had the same thing happen