512.73 is the Dewey Decimal system classification for analytical number theory.
What is the significance of 512.73?
According to "The Penguin Dictionary of Curious and Interesting Numbers":
First I subtract it from 666, the Number of the Beast in the Book of Revelation:
666 - 512.73 = 153.27
The same digits appear, but rearranged, signifying the effect of removing evil from the world.
The whole number part is now 153, the number of fishes hauled from the river by Peter.
The decimal part is the sacred number 3, raised to its own power.
Divide the Number of the Beast by 3, and you obtain 222,
the Dewey Decimal system classification for the Old Testament.
Add 3 and you obtain 225, the classification for the New Testament.
Add 3 again, and you obtain 228, the classification of the Book of Revelation.