What Does The Number Next to My Name Mean? And How Do I Raise It?

I was wondering what the number next to my name, per the photo means? And also how do I raise this number?

Does the number rise by the number of posts I have? By how much Steem Power I have? By the amount of STEEM I hold?

I know it has something to do with my rank and what not on the site but not curious what it signifies and what factors make it go up?