Otis -- who's also an heir to the Otis Elevator Company fortune -- made his way to the top of the Empire State Building Thursday morning and dropped thousands of gold flyers down upon the city.

Otis says he explained to the building authorities that what he did was a non-violent act to spread the word about President Trump's incessant lying ...

he says he's now banned for life from the Empire State Building.

As for the flyers, Otis says they were printed on both sides with more than 20,000 examples of lies Trump has told in office ...