Bieber has held on to the spot since January after he toppled Lady Gaga's then 33.3 million-strong following Gaga currently has 40.39 million followers on Twitter, but she is number one on Facebook, in which she has 60.35 million "likes."
Last week, Katy had her second number-one debut as new album "PRISM" topped the Billboard 200 chart. "PRISM" sold 286,000 copies, passing Miley Cyrus for the highest selling debut of the year for a female artist.
Meanwhile, authorities in Australia declared her new album a biohazard due to the small packets of seeds that are included with the record.
The singer included the seeds with her album to encourage fans to "plant to spread the light!" She is currently in Japan promoting the project.