16 March 2012
That number is "Belphegor's Prime" - a palindromic prime with "666" in the center, flanked by 13 zeroes. The symbol for it is a bird glyph (right) found in the Voynich manuscript.
Belphegor was one of the seven princes of Hell, who seduced people "by suggesting to them ingenious inventions that will make them rich."
Image of Belphegor (seated on what appears to be a "close-stool") credit to J.A.S. Collin de Plancy, in the Dictionnaire Infernal, Paris : E. Plon, 1863. Page 55, via ZTF News.
Via Dr. Cliff Pickover and Neatorama. Can math wizards here offer any additional insights on the derivation or usage of the number?