16 million people saw it.
Oops!
Katy Perry accidentally shared her phone number with her 16 million Instagram followers.
Watch Katy Perry's halftime secrets.
It happened when she posted pictures and video of her dog named Butters. When Katy posted the video you could clearly see the phone number on Butters' dog tag.
Watch 'A dog sent me to prison.'
Her fans tried to alert Katy. One fan tweeted: "Do you realize there's a phone number in that?"
Another fan said: "I don't know if it's your phone number but you should kinda see this."
Katy quickly changed her number and deleted the video.