Britney Spears teams up with Nicki Minaj, Ke$ha for remix

A remix of Britney Spears' single 'Till The World Ends' has leaked online.
The song features a rap from Nicki Minaj and vocals by Ke$ha, who penned the track.
Teasing the release on Twitter, Spears wrote: "Sicker than the remix," while Ke$ha said: "Next one on my hit list." Both tweets linked to a cryptic countdown to Monday, which could suggest the release date for the track. 
Hear the 'Till The World Ends' remix featuring Nicki Minaj and Ke$ha below.