Millennials have an enduring reputation for being dumb about many things.

Clearly, that’s a bum rap. They’re just ignorant about some stuff.

They know a lot about “The Bachelor” and “Star Wars.” They can text more than 60 words per minute. They know that George W. Bush was responsible for more deaths than Joseph Stalin. They know that capitalism is a dangerous concept and communism isn’t really a problem. They are unfamiliar with that Lenin fellow and Mao Tse-tung, who are dead, by the way. So, why bother knowing or caring?

Yes, sure, three-quarters of millennial parents are still paying some of their adult children’s bills, as our Jazz Shaw has noted. And thanks to the Federal Trade Commission, Jazz was able to show that Americans in their twenties who are so good adept at taking selfies, are easily the most susceptible to scams, not grandparents in their seventies.

So, it was quite encouraging to learn the other day that fully one-in-three millennials knows what Auschwitz was. Yes, yes, that means that two-thirds of this hip new generation never heard of the infamous Nazi death camp.

The same survey found that just over half of millennials knew that six million Jews were killed in the Holocaust. That’s one-third of all Jews on Earth at the time. Of course, that also means that 41 percent of that huge generation hadn’t a clue how many members of one religious faith perished during that horrendous chapter. That’s no big deal. It’s over, right?

“There remain troubling gaps in Holocaust awareness while survivors are still with us,” said Greg Schneider of the Claims Conference. “Imagine when there are no longer survivors here to tell their stories.”

A substantial majority of American adults in the survey (70 percent) — agreed that awareness of the Holocaust is declining. And 58 percent of Americans said they believe that something like the Holocaust could happen again,which is silly. Just ask a millennial living in the basement next door.