Republican John McCain, who has spent much of the summer trying to characterize his Democratic opponent, Barack Obama, as a rich elitist and celebrity, couldn't tell a reporter Wednesday how many homes he owns with his wife, Cindy.

"I'll have my staff get to you," McCain said in an interview with The Politico. "It's condominiums where -- I'll have them get to you."

McCain's staff later reported that McCain owned at least four homes, in Arizona, California and Virginia. Newsweek magazine said the couple owns at least seven properties.

His wife, Cindy, has an estimated worth of more than $100 million, in part through inheriting control of her father's beer distributorship, the largest in Arizona.

According to her 2006 tax returns, Cindy McCain had a total income of $6 million. She has not released her 2007 returns, which she files separately from her husband. McCain's tax returns showed a total income of $405,409 in 2007.

The remarks came as Obama's campaign and its allies have hit back hard against McCain since the Republican began airing ads that compared Obama to Hollywood celebrities such as Paris Hilton and Britney Spears.

"He's the biggest celebrity in the world, but is he ready to lead?" the voiceover asks in the ad, which mixed images of Obama on his trip to Europe with video of the celebrities.

Hilton had some fun of her own in response, tweaking the McCain spot in an online video.

"That wrinkly, white-haired guy used me in his campaign ad, which I guess means I'm running for president. So thanks for the endorsement white-haired dude," she says in the video.

And a new radio ad running in battleground states says, "Celebrities like to spend their millions. Barack Obama is no different. Only it's your money he wants to spend."

Meanwhile, the Web site Wilshire and Washington, published by Variety magazine, reported McCain will be paying a visit to some other celebrities when he travels to Los Angeles Monday for an appearance on "The Tonight Show."

McCain will attend a fundraiser at the Beverly Hilton, an event Angie Harmon, David Zucker, Jon Cryer, Craig T. Nelson, Jon Voight, Craig Haffner and Robert Duvall are expected to attend, the Web site said.

McCain has been tweaked for wearing a pair of $520 Italian shoes on the campaign trail. And when he was recently asked to define "rich" in an interview with megachurch pastor Rick Warren, he offered $5 million as a starting point -- although he more broadly defined personal wealth in terms of home ownership, education, a good job and a more prosperous world.

Obama answered a similar question with Warren, saying those making $250,000 and higher are in the top 3 to 4 percent and "doing well." The Democrat and his wife reported earnings of more than $4 million last year.