The fifth power of a thousand, i.e. 10^15, as opposed to a short-scale
quintillion which, irrationally, is the sixth power of a thousand, i.e. 10^18, and a long-scale quisntillion which is the fifth power of a million, i.e. 10^30. "Pentillion" belongs to a
consistent system for naming large numbers proposed in 2001 by a member of the
University of North Carolina.