Executives at Instagram celebrated its fifth anniversary on Tuesday (06Oct15), and for the first time, they confirmed the top five accounts followed by more than 400 million users around the world.

The Shake It Off singer leads the all-female list with an impressive 50 million, and took to the app on Thursday (08Oct15) to share her gratitude by writing, "50 million followers!! Thanks so much guys. I'm pretty sure this is just because I have cute cats though."

Following closely behind is reality TV star Kim Kardashian with 48.1 million and R&B singer Beyonce comes in third place with 47.2 million.

Pop stars Selena Gomez and Ariana Grande round out the top five with 45.9 million and 44.6 million fans respectively.