How big is a sextillion

A sextillion equals 10^21 in the short scale system (American/modern international usage)—that's 1 followed by 21 zeros. In the long scale system (historical European), it equals 10^36. Given modern standardization on the short scale, sextillion typically refers to the 21-zero version.

Numbers of this magnitude exceed almost all practical applications. The estimated number of stars in the observable universe is roughly a few hundred billion to a trillion (far less than a sextillion), though the number of grains of sand on all Earth's beaches might approach sextillion-scale. In computing, theoretical calculations about possible states in complex systems might reach these magnitudes, but scientists working with such large quantities invariably use scientific notation (10^21) rather than saying "sextillion." These extreme number names exist as part of the systematic Latin-based naming convention, but they function more as mathematical curiosities than practical tools for describing quantities anyone actually encounters.