Selena Gomez has gotten the best belated birthday present ever: her first #1 album.

Stars Dance, Selena's fourth studio album but her first billed as a solo artist without her band The Scene, has debuted at the top of the Billboard album chart.  Not only is it her first chart-topping disc, but its first-week numbers, 97,000 copies, according to Nielsen Soundscan marks the singer's best-ever sales week.

Selena's last three albums, Kiss and Tell, A Year Without Rain and When the Sun Goes Down peaked at #9, #4 and #3, respectively.

Selena, who's 21, is also the youngest female solo artist to score a #1 album since her BFF Taylor Swift did it in 2010 with Speak Now.  At the time, Taylor was 20.

Selena's world tour launches August 14 in Vancouver, Canada.  Her new single "Slow Down" will hit radio August 12.

On the acting front, Selena's new movie, The Getaway, arrives in theaters August 30.