How much mining power is required to have a 1 in a million shot taken once per week of (solo) mining a block?

Side question: How would I go about answering this question myself in future?

Ideally I'd like a formula to plug current values into. But ballpark answers are of course welcome.

Thank you for your time šŸ™‚

Submitted July 18, 2017 at 09:09AM by Innomen
via reddit