Whats the nnumber next to your gamertag mean?

I see everyone has a number next to their tag and i want to know what that means and how high does it go.

It’s your SR rank, which is based off of EXP. I think the max level is 152? Or something very close to that number

A time played counter in the form of Experienced earned for spending time in matchmaking.

I think you can earn a bonus 1% for winning games.

The max is 152 which is obtainable by gaining 50,000,000 exp.