Ariana Grande Surprised with the Success of Her Hit 'Problem' (@ArianaGrande @IggyAzalea)

Ariana Grande's hit single "Problem" featuring Iggy Azalea has made Billboard history and help gain the singer her first number hit, but the singer was unsure about the song when she recorded it.

In an interview with Ryan Seacrest, the singer says she forgot about the song and didn't think it would do well.

"I had no idea "Problem" was going to be on the album," she said. "Until I heard the final mix of the song, I forgot about it for a little and I didn't hear it until it was done and mastered and it was a different moment. I was like 'Oh, maybe I was wrong about that one.'"

"Problem" may be a big hit for the singer, but her collaboration with Big Sean is her favorite.

"I did another song with one of my best friends Big Sean," she said. "It's called "My Biggest Mistake" and it's one of my faves."

Check out the rest of the interview above.

Source: YouTube