So, exactly how rich is Richie Rich, aka Donald J. Trump?

“None of your business.”

That’s what the presumptive Republican nominee for president told George Stephanopoulos the other day on “Good Morning America,” when George had the gall to ask Trump when the country might get a look at his tax returns.

For the last 11 months, at every campaign rally, his stand-up shtick has always been punctuated with the declaration, “I’m really rich. I mean really rich.”

Over and over again, we’ve heard The Donald assure us he was rich enough to self-fund his own campaign. “I’m a self-funder. I’m not taking any money, OK?”

All those other RINO leeches who had to beg for money and suck up to super PACs during the primary campaign — Lyin’ Ted, Little Marco, Low Energy Jeb, Ugly Carly … well, self-funding Donald vanquished them all.

As Donald crisscrossed the country in his Trump jet, so much bigger than Hugh Hef­ner’s infamous Bunny jet, the figure of $10 billion seemed to follow him everywhere.

Now, on the threshold of his solo flight for the presidency, comes the Jabba the Hutt vision of a Las Vegas casino mogul, and Dorchester homeboy, Sheldon G. Adelson, who says he stands ready to generate $1 billion to fund Donald’s effort to turn the White House into the Trump House.

I’m pretty horrible when it comes to math, but it seems to me if you claim to be worth somewhere in the neighborhood of $10 billion, you should be able to handle a lousy ?$1 billion to self-fund your way to the White House — without turning to a Vegas Jabba. No?

Of course, the red hat legions of Donald zombies won’t care about any of this. They will happily buy whatever Donald feeds them, because he’s not going to offer any hard proof of just how big, or small, his fortune really is.

In giving the one-fingered salute to a universe of liberal, lefty, commie media tax gawkers, Donald Trump has actually provided “Crooked Hillary Clinton” and her sister from another mother, “Goofy, Fake Indian Elizabeth Warren,” with a big fat rejoinder.

Whenever Donald demands to see the transcripts of Hillary’s speeches to Wall Street, she’ll be able to say, “Sure Donald, right after I see your tax returns.”

U.S. Rep. Michael Capuano hit the nail right on the head when he told me yesterday, “If Richard Nixon could release his tax returns 45 years ago, then you have to wonder what’s the matter with Donald Trump.”