Although, it seems as though Imangi is only counting Temple Run and Temple Run 2, not the Disney branded versions - Temple Run: Oz and Temple Run: Brave. Imangi is counting all of the downloads across Android, iOS, and Windows Phone for the two games though. In addition to the download numbers, Imangi is giving out some demographics info as well. Apparently, 60% of players are female, but it is unclear how Imangi got that data. Imangi has also said that the game is most popular in China, which has accounted for 36% of downloads, with the US in second place with 21% of all downloads.
The game is clearly very popular, and has been popular enough that there is a movie planned which will be based on it. Of course, movies based on video games don't have such a great track record, so we're not holding out much hope on that.
source: The Verge