No there weren’t. They are correctly classified as skeptics or doubters. They were most certainly not what we would call atheists (e.g. Bertrand Russell or Christopher Hitchens).
Yes there absolutely were. You can have your own opinion, but you don’t get your own facts. And the FACT is there WERE atheists in the pagan world. Just because they weren’t $%^holes like Hitchens doesn’t mean they weren’t atheists.