(Photo credit: @justinbieber/Instagram)

Justin Bieber is no longer the most popular star on Twitter ( that's you, Katy Perry!), but he's still got bragging rights to Instagram.

In 2013, the number-one liked photo on Instagram was this shot that Bieber, 19, posted four months ago.

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"Me and uncle Will," he wrote, next to a photo of himself with Will Smith.

More than 1.5 million people liked it - just a fraction of Bieber's 12,000,000-plus followers.

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In a recent Hollywood Reporter interview, it was revealed that Smith has been a great mentor to the teen heartthrob. Bieber's manager, Scooter Braun, said that Smith has a weekly phone call to discuss life.

"He's telling me: 'Justin's got to go through it. You can't stop him from going through it,'" Braun said. "'That's youth in itself. He's a young man who's growing up, and that's what makes him interesting and relatable. Otherwise, he'd be some kind of weird robot.'"