Justin Bieber Reveals New Single Details, Gets Birthday Surprise on 'Ellen DeGeneres Show' (Video)

Michael Rozman/Warner Bros.

Justin Bieber turned 18 in a very special way -- by appearing on Ellen DeGeneres' talk show.

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But it wasn't all about his birthday. The singer had wrote Feb. 28 on his Twitter account to his nearly 18 million followers that he had some big news to share: "i got something BIG to share with you and the world this week. thank u for everything! see u soon."

When asked by DeGeneres what the big announcement was, Bieber revealed information on his new single off Believe.

"My big announcement is that on March 26th, my first single is coming out and it's called 'Boyfriend,' " Bieber told the audience.

The reason for the name of the song, which he co-wrote with Mike Posner, was simple. "Basically I'm talking to this girl, if I was your boyfriend, I would never let you go," Bieber explained.

The most memorable moment of all came when manager Scooter Braun surprised Bieber with a birthday gift. After listing off Bieber's charitable ways, including meeting with a Make-a-Wish kid after every show for 86 dates during his tour, Braun showed off Bieber's new car: a new (and hard-to-get) Fisker Karma.

Not to be outdone, DeGeneres put her own spin on her gift to Bieber: sun shade with a heart over DeGeneres and Bieber, as well as a bobblehead.

Bieber's appearance on The Ellen Show airs Thursday.

Watch the videos below: