He later upgraded his residence, buying property over the years at the United Nations Plaza , at 740 Park Avenue and in Southampton .

Mr. Koch made his fortune in the family business, the energy and chemicals conglomerate Koch Industries, and founded its New York City office.

He was very rich. And was apparently enjoying life in New York.

In 1980, he ran for vice president as a member of the Libertarian Party. New York magazine, which interviewed Mr. Koch at the time, described him as “a 40-year-old former all-American basketball center from M.I.T., a bachelor corporation president who lives in a rent-stabilized, one-bedroom apartment on Central Park South.”

“He still reads, dates a lot, and likes to summer in the Hamptons,” the magazine said. “Weekends, he skis or studies pollution-control designs at the office, attending society gatherings ‘dragged, kicking and screaming, by a girlfriend.’”

His New York philanthropy

Mr. Koch donated $20 million to the American Museum of Natural History, which named a dinosaur wing for him.

He gave $65 million to the Metropolitan Museum of Art, which named a plaza after him.

He gave $100 million to Lincoln Center, a donation that The Times called “transformative” for the center’s New York State Theater, “enabling a full-scale renovation of the stage, complete with an enlarged orchestra pit that mechanically rises.” The theater is now known as the David H. Koch Theater and is home to New York City Ballet and American Ballet Theater.

He gave $100 million to NewYork-Presbyterian Hospital and $150 million to Memorial Sloan Kettering Cancer Center. Both have facilities bearing Mr. Koch’s name.