that # is the amount of points you have. if you go to settings, you can see how many points you need to get to to unlock the next icon. when you get 1000 points, you can add memes to your comments, and at 2000 you can add a tagline to your profile. at 10000 points, you can access certain streams (those streams only allow users with 10000 points) and you can make a custom Icon.
