Updated: “We have Donald Trump on the show tonight,” Jimmy Fallon said at the top of The Tonight Show. “I’m not saying security is tight, but the Secret Service just built a giant wall around the building. And we had to pay for it.”

“You must be really, really, really excited now – because the Powerball’s at $1.3 billion,” Fallon told Trump when he came out. “What would you do with all that money,” Fallon joked – because, of course, Trump so rich he would not be excited about $1.3 billion, right?

“I don’t know,” Trump responded, smiling. “It all goes to the vets — you like that idea?” he asked the audience.

“I don’t know what you’re going to say or do next,” Fallon said of Trump’s campaign. “It’s kind of exciting to watch the debates – you say things and I’m like, ‘Oh, that’ a little controversial!'” As a for instance, Fallon brought up Trump’s No Muslims Welcome proposal. “Temporary basis,” Trump jumped in, noting applause in the studio. “One person,” Fallon pointed out.

Trump credited himself with having started a dialogue all over the world: “At a minimum we’re getting a dialogue started so we can have a conversation.”

They spent a good-ish deal of time tonight talking about Democratic presidential front-runner Hillary Clinton. “I think she’ll win [the Dem nomination], I guess,” Trump said.

Fallon thought he heard Trump “say something that Bill campaigning for [Hillary] is not a smart idea.”

Related Story Carly Fiorina Back To Kids Table For Thursday's GOP Debate On FBN

“Well, I don’t know — I mean time will tell,” Trump responded, coyly. “She came out with a little bit of a statement about me, and I came out with a very big statement about her and Bill. And she stopped talking about me all of a sudden. But, you know, I don’t know.”

They agreed Bill Clinton is a “charming guy.”

Trump forecast this is “going to be one of the most interesting races.”

Too late – it already is.

“They actually said if I win – a poll came out – if I win and she wins, it’s going to be the largest voter turnout in the history of the country. And that’s a good thing, because people don’t vote that much in this country,” Trump said. “So that would be an amazing thing if that happened.”

Fallon asked about the on-again/off-again conspiracy theory “that you were hired by the Democratic Party so that the Clintons would win.”

“Well, I mean they like to start that,” Trump simpered, without saying who is “they.”

PREVIOUSLY: GOP front-runner Donald Trump this afternoon sent a reminder he’s Jimmy Fallon’s guest on this evening’s The Tonight Show – three nights before the next GOP debate, on Fox Business Network. The GOP front-runner previously visited the Jimmy Fallon-hosted talker on September 11 — the first time Trump had been a guest on a late-night talk show since announcing his White House bid in June.

The Donald and NBC had been at odds last summer after NBC followed Univision in dropping the Trump-run Miss Universe and Miss USA pageants in the wake of the candidate’s controversial comments about undocumented immigrants coming over the Mexican border. Since then, relations between Trump and NBC have been much better, with Trump scoring big ratings and buzz when he hosted Saturday Night Live in November.