The taxes are not included in that figure. That’s the actual prize pool money they’d have on hand in case of a win. The advertised jackpot is an estimate of an annuity paid off investing that prize pool in securities over the course of 30 years
The lottery will withhold 24% for federal income tax – but you’d likely owe more as the vast majority of that income will wind up taxed at 37%. Then there’s also state income taxes in most places.
If I win this jackpot and take the lump sum it would break down something like: