The world according to Robin

He’s won an Oscar, two Emmys, five Golden Globes and five Grammys. He’s Mrs. Doubtfire. Garp. Genie.

He’s Robin Williams, the notorious motor mouth, the man whose standup routines garnered acclaim for their off-the-wall craziness and their ability to change course in an instant. Mostly though, he’s a guy who’s been making us laugh since the late 1970s, when he donned a red spacesuit and said “Nanu nanu.”

In a telephone interview this week in advance of his Monday performance with longtime friend David Steinberg at the Martin Woldson Theater at The Fox, Williams was most eager to talk about his current tour, “An Evening of Sit Down.”

So how, exactly, do two old friends have nightly conversations on stage and keep them interesting? It helps, Williams said, that he and Steinberg both have backgrounds in improv, Steinberg at Chicago’s Second City and Williams in college and at The Committee in San Francisco.

“Every night is different,” he said. “It’s really sweet because we can play off of each other really well that way.”

And yes, certain subjects do crop up every night.

“Pretty much our lives,” Williams said. “Things that have happened in both of our careers. We try to mix and match and also we’ve been finding new stuff to talk about.”

Steinberg’s career, in fact, has offered up some rich stories, Williams said. Steinberg was one of Johnny Carson’s favorite guests on “The Tonight Show,” with 130 appearances, second only to Bob Hope. He’s had a prolific career as a television director, working on such shows as “Curb Your Enthusiasm,” “Mad About You,” “Designing Women,” “Seinfeld” and “Golden Girls.” He wrote for “The Smothers Brothers Comedy Hour,” and used to hang out with Groucho Marx.

“Knowing Groucho Marx, which for me is just amazing,” Williams said. “Knowing that he hung out with him, I’m going (in a dead-on Marx impersonation) ‘That to me is a wonderful evening.’ ”

Williams and Steinberg have been friends for years. The inspiration for the tour came from Steinberg’s earlier series “Sit Down Comedy With David Steinberg” on TVLand and his current show “Inside Comedy” on Showtime, in which he interviews comedians.

“He’s so laid back, but he’s also stone cold brilliant and really funny. And he’s a comic himself, so he can kick out there when needed, too,” Williams said. “That’s what makes it easy … He has stuff that’s really amazing. Stories about him and (Richard) Pryor, stories about him directing ‘Golden Girls’ ” – he laughs at the memory – “that are pretty wonderful.”

Williams is as at home on stage as he is on the soundstage, having performed in sold-out concert halls, big crowd-pleasing films and hit TV shows. Still, performing live, he said, is “totally different” from acting.

“It’s exhilarating and frightening at the same time,” he said. “The good news is, it’s me; the bad news is, it’s me. You’ve got to be ready for it. Doing standup, I think Chris Rock said it, you have to be like a prizefighter. You have to be ready, you have to be in shape …

“This is a little bit different. It’s two of us. It’s more like jazz, back and forth,” he said.

He still likes to get out and stretch his standup legs when he can. While shooting a movie in New York called “The Angriest Man in Brooklyn,” he did some sets at usual haunts like Comedy Cellar. He also did a show at The Kitchen in Brooklyn.

“The stage was as big as a small throw rug. But it was good to try to see what worked and what didn’t work and then go, ‘OK put it out there old man, let’s see what you got,’ ” Williams said. “Then when you’re doing these shows, sometimes you have to say, ‘Turn off your phone just for a moment. Don’t film me. Just let me try something. This isn’t for public consumption yet.’ …

“That’s the joy of it. You literally have to say (slipping into one of his voices), ‘Not now. Let’s just have this moment. Let’s just do this now.’ ”

On Monday night, fans at the Fox will not see Williams spend the whole night stuck in his chair.

“It’s mainly me getting up. David doesn’t get up much. I’m the one who bursts out of the chair occasionally,” he said, “and I have to get up and re-enact something.”

He ends our interview with a riff. When asked what the people in Spokane can expect on Monday night, his reply is instant and hilarious:

“Full-frontal nudity. It’ll be ‘Welcome to Sugar Daddies, a club where old men dance for young girls.’ ” He laughs. “No. Not even topless. It becomes an animal rights issue with me.”