Well, I don't know if it's helping but I found this : the number one represent the son of God.. The number that represent life, the "real" (or the reality)that comes through the 0 the infinity. That's meaning the purity and the new beginning.
The number 3 represents the pure joy of creativity. It refers to the past the present and the futur.
Finally, the 13 could mean a lot of things... the creativity the emotions... and many many more.
I know that Michael loved to put some reference to numbers, artists ou spirituality in this creations. In this case, I think that it could be one of.