I will guess #680.
If you hover your cursor over your ID, and look at the link, right near the end it says userid=XXX. I think XXX=the order that you signed up. In your case XXX=680. For Rikki, she is #5949. I am #2033.
I think we should go 'Stonecutter' style and refer to each other by number in the order we joined.
That's just my theory. Good day #680...