Question about equation for LT3750 capacitor charger IC
Since 0.00002µH sounds way too small, I would assume 20µH.  This hunch is further backed up by the chart of recommended transformers on the same page.

If they wanted you to use 0.000001 in the numerator, they would have written it differently in the datasheet.

Since this equation is very similar to

you can hopefully see what they are getting at.

If you convert the seconds to microseconds, you are also changing the henry to microhenry.  So your first equation is correct if you change the units in the answer to H instead of µH.