(10,000,000) / (20) = 500,000
(10,000,000) * (0.069) = 690,000 in taxes.
So (10,000,000) - (690,000) = 9,310,000 in a lump sum.
In 20 payments it would be $500,000 minus the taxes.
($500,000) - [(690,000)/(20)]
($500,000) - [$34,500] = $465,500
One lump sum would be $9,310,00. If they don't charge you taxes if you get the 20 payments per year, you would get $500,000. If you're charged taxes you'd get $465,500 per year.