Information Content of the Universe Norretranders, The User Illusion, 1998
"The integer that describes the entropy of the visible universe, the number of bits in the universe, is written as a 1 followed by 88 zeros. If we compressed the entire universe into a black hole, the entropy would be somewhat greater: The number of bits would be represented by a 1 followed by 120 zeros."
"But how big was the entropy at the Planck time?"