Upper Bound for Number of Grains of Sand to fill Universe/Mistake

Source Work

 * The Dictionary
 * $10^{51}$
 * $10^{51}$

Mistake

 * ... the number of grains of sand required to fill the universe turns out to be, in our notation, less than $10^{51}$.

Other sources report it as $10^{63}$. It is not clear from where sources his information.