Justin Bieber has a man crush on Ben Affleck.

The 21-year-old singer is a huge admirer of the 42-year-old actor because of his success and the way he conducts himself.

When asked who his man crush is, Bieber named 'Batman v Superman: Dawn of Justice' star Affleck, adding: ''I think his vibe is cool.''

Bieber also admitted he wishes he had an alter-ego like Affleck's superhero character, so he could just disappear when the attention from the paparazzi and the public got too much.

In an interview in the new issue of Men's Health magazine, he said: ''I wish I had the Batman thing where people didn't know I was Bruce Wayne. Like I had a costume or something.''

Explaining how odd he finds his level of fame, he added: ''I never thought I'd see my own billboard on Sunset, in Hollywood. I remember just thinking that I'd never even go to Hollywood, living in a small town in Canada, just watching TV. That was never even a thought.''

Despite being one of the biggest pop stars in the world, the 'Heartbreaker' hitmaker insists he isn't ''self-centred'' but he does think he's different to a lot of people.

Bieber - who was discovered when he was just 13 - mused: ''I've always been different, and I haven't been afraid to be different.''