Remember in the early days of Twitter, when Ashton Kutcher was pretty much the only well-known celebrity on the social media outlet and it was a huge deal when he reached 1 million followers?

Well, the first person to reach 100 million followers has just hit that milestone.

It's not Justin Bieber, or Donald Trump, or Barack Obama or any of the One Direction minions... heck, it's not even Taylor Swift.

Pop star Katy Perry reached the remarkable milestone in recent days, with her closest rivals on 96.7 million (Bieber) and 90.8 million (Obama). She clocked up her huge number of followers since joining Twitter in February 2009, and now has the ear of 100 million of the world's citizens.

Twitter made the announcement with a congratulatory tweet, which you can see below: