Justin Bieber joins Katy Perry in 100 million Twitter club

Justin Bieber has become only the second person to land 100 million Twitter followers.

The pop star joins Katy Perry as the only two people to hit the magical social media feat, with Taylor Swift a distant third with 85.5 million followers.

Rihanna (76.9 million) and Lady Gaga (69.5 million) round out the top five.

Meanwhile, according to Twitter statisticians, Bieber has been mentioned more than two billion times on the microblogging outlet and his most retweeted message has more than 638,000 retweets.