Washington DC - President Donald Trump bizarrely riffed on some of his White House predecessors during a special US 250th birthday episode of Second Lady Usha Vance's children's podcast.

Speaking with Vance on "Storytime with the Second Lady," for a special episode commemorating the US' 250th anniversary, the billionaire property tycoon and two-time president opened with his favorite topic – real estate.

The pair were sitting in the Oval Office: "It's the most powerful piece of real estate, probably in the world. Everything starts here, ends here, starts again."

Sat next to a pile of books and a plush bald eagle, Trump felt the need to tell the podcast's audience – mostly children – that he doesn't have time to read.

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"I end up reading mostly newspapers. I usually read stories about myself," he said.

Picking up an illustrated book about US presidents, Trump started riffing on former White House occupants, offering a stream of commentary as he flipped through.

Abraham Lincoln rode horses: "I'd like to ride horses, too," Trump said, but warned of the risks of falling off.

John Quincy Adams swam in a nearby creek: "I think we're building a beautiful ballroom on top of it, based on this picture."

Franklin D Roosevelt swam in an indoor pool which today is the White House press room, while Gerald Ford enjoyed an outdoor pool, Trump said.

"I don't know if I look good in a bathing suit. I haven't had a bathing suit in a long time. I'm too busy."

John F. Kennedy was a sailor and "the second most good-looking president," Trump said, leaving unsaid who's the first. Bill Clinton "actually was a nice guy."

Trump said another foe, Barack Obama, liked to shoot hoops, but cautioned it wasn't a compliment: "I don't know if he's a good basketball player. I tend to doubt it."