The art piece depicting the former POTUS was erected -- no pun intended -- just outside Las Vegas ... towering over Interstate 15 on the way to Utah. We've had to blur the pics a bit here, but you get the basic idea -- the prez wears no clothes.

Sources with direct knowledge tell us the statue stands 43-feet-tall and bears the name "Crooked and Obscene" ... a reference, we're told, to the controversial nature of both the man and the statue itself.

The statue is constructed from foam over rebar and weighs around 6,000 lbs. It's a marionette -- yes, those massive arms move. As for his other appendages ... we're less sure about that.

Nudie Trump went up Friday evening ... and, there's no telling when it may come down. We're told the team behind the piece wants to start conversations about the election -- so, barring some sort of outrage, this would seemingly stay up through early November.

Remember, not the first time Trump's been immortalized in all his glory. When he was running for president in 2016, a series of naked statues appeared in public ... featuring the Republican candidate totally nude with just a tuft of yellow hair covering his you-know-what.

The mystery of where they came from was so popular, Zak Bagans even purchased one for his Haunted Museum in Vegas ... throwing down about $28k for one of these beauties.