So naturally, Jimmy Fallon had to do something about it to mark this milestone! An experiment, if you will!
Jimmy in the Big Apple pitted his show writer Arthur Meyer against the Roar singer to see who can get the most retweets on Twitter by tweeting the exact same thing that Katy tweets.
We're not sure how long this will be going on for, but this is day one of his retweet experiment!
Take a look at the outstanding number of retweets between Katy & Jimmy's writer (above)!!