FIRST LISTEN: Britney Spears and Iggy Azalea's 'Pretty Girls'!

Just a few days after it was leaked on line, the new song "Pretty Girls" from Britney Spears and Iggy Azalea is officially out today. Get a first listen below!

Six-time Billboard Music Award winner Britney Spears has charted six No. 1 albums on the Billboard 200 and five No. 1 songs on the Billboard Hot 100. Among her hit singles are the No. 1 smashes "...Baby One More Time," "Womanizer," "3" and "Hold It Against Me." She has sold 33.1 million albums in the United States, according to Nielsen Music.

In the past year, Iggy Azalea became the first act since The Beatles to chart at Nos. 1 and 2 simultaneously on the Billboard Hot 100 chart with their first two hits. Those songs - "Fancy," and Ariana Grande's "Problem," featuring Azalea -- were the first of six top 40 hits for the rapper, who later scored with tracks like "Black Widow" and "Beg for It." When Azalea's debut album The New Classic debuted on the Billboard 200 chart, it was the highest-charting rap album by a woman in nearly three years. This year, Iggy is a finalist in 11 categories with 12 entries, competing against herself for Top Rap Song for her hits "Fancy" featuring Charli XCX and "Black Widow" featuring Rita Ora.