The "Iron Man" movie series is a gift that keeps on giving to Disney, and the presents keep getting bigger.

The latest sequel of the Iron Man superhero, Iron Man 3, is bigger than ever with a $175.3 million opening weekend in the U.S. in its first three days in North America at 4,253 theaters. 

The film averaged $41,218 per theater and received a big boost from IMAX screens, which accounted for $16.5 million of its opening weekend gross. About half (45%) of tickets sold were in the 3D format.

Iron Man 3 had the second-biggest debut ever, behind the $207.4 million start last year for The Avengers, which teamed him with other Marvel Comics heroes Thor, the Hulk, Captain America and others.

Iron Man 3 opened a week earlier in other countries has brought in $504.8 million internationally, giving the blockbuster movie a worldwide total of $680.1 million. Iron Man 2 made the $312 million international total in its entire theatrical run.

Iron Man 3 has widely outsold the first two movies in the Iron Man movie run. Iron Man launched the series with a $98.6 million domestic debut in 2008, while 2010's Iron Man 2 opened with $128.1 million

Dave Hollis, Disney's head of distribution, says The Avengers' popularity has definitely played a key part in Iron Man 3's success - and hopes to boost prospects of both the Thor and Captain America franchises as well. "We sat here a year ago with The Avengers, and there was speculation of what the impact of what such a big weekend and the coming together of all these heroes might mean for each of the subsequent films," he says, "and we're first-hand witnessing that the brand is as strong as it's ever been."

Iron Man 3 earned a solid "A" CinemaScore but faces high competition over the next few weeks from Star Trek Into Darkness and Fast & Furious 6. 

Will Iron Man 3 win the summer box office crown?