There may have been two winning tickets for that $587.5 million Powerball jackpot last month, but there were three big winners.

Mark and Cindy Hill of Dearborn, Mo., opted to take their half of the big prize in a lump sum of $193,750,000, and it’s likely that whoever bought the other winning ticket in Fountain Hills, Ariz., will do the same thing. But a whopping share of the jackpot will go to a greedy uninvited partner who didn’t even bother to play: Uncle Sam.

The Internal Revenue Service treats lottery winnings as ordinary income, and a ninefigure income is subject to the highest federal tax rate of 35 percent. That means the first thing the Hills had to do after landing their big prize was surrender $67 million of it to the U.S. Treasury.

The lucky owner(s) of the Arizona ticket will fork over the same amount. There are also state taxes to kiss goodbye.

In Missouri, where the income tax rate is 4 percent, the Hills will be charged almost $8 million; the Arizona winner will pay at least 5 percent: nearly $10 million.

Admittedly, few of us will lie awake at night in despair over the Powerball winners’ tax bill. Even after rendering unto Caesar what is Ceasar’s, the big winners will clear more than $110 million each. Money may not buy happiness, but $110 million can certainly buy a reasonable facsimile of it.

Yet the taxman doesn’t just take a bite out of the biggest winners. The IRS helps itself to a hefty chunk of every smaller jackpot too.

Three elderly gents in Oklahoma who bought a winning $1 million ticket each took home $236,667 after taxes, the Tulsa World reported last week.

Sure, that’s a lot better than throwing away a losing ticket.

But when the government sells you a chance to win a million dollars that actually pays only 700 grand, it hasn’t really sold you a chance to win a million dollars, has it?

Income taxes paid on lottery prizes are only the tip of the iceberg.

The billions netted by the IRS from Powerball, MegaMillions and their forerunners over the years are dwarfed by the tens of billions raked in by state lotteries every year.

In 2011-12, the nation’s 44 state lottery commissions cleared $60.8 billion in their ticket sales; according to the Los Angeles Times, 32 of those states broke their previous sales records.

But unlike private casinos, where payouts of 90 percent or more at slot machines are common, state lotteries typically pay out an average of only 60 percent of their revenue in prizes.

In 2010, the Tax Foundation calculated the average nationwide tax rate represented by lottery tickets at a steep 43.7 percent — not including those aforementioned taxes on winnings.

It’s a rotten deal for players, only partly mitigated by the fact that no one is forced to buy a lottery ticket.

The “cruel truth” about state lotteries is not just that people who can least afford to buy tickets are the likeliest to buy them. It is that the government, spending public funds, “goes out of its way to tell them it is a good idea.”

By all means, be happy for the folks who bought those winning Powerball tickets. Just don’t make the mistake of thinking lotteries are about them.

Lotteries are designed to enrich the government.

JEFF JACOBY writes for the New York Times News Service