DOCTOR: Erato, we did it!

ERATO: I still it was impossible.

ROMANA: So do I, though I did calculate our changes of success at seventy four million three hundred and eighty four thousand three hundred and thirty eight to one against.

DOCTOR: What? Seventy four million three hundred and eighty four thousand three hundred and thirty eight? Well, that's extraordinary.

ROMANA: Why?

DOCTOR: Well, that's my lucky number.