Peta-

Peta- is an SI prefix meaning one quadrillion.SI brochure, Section 3.1 on BIPM site Its name comes from Greek "pente" meaning five. The name was formed on the analogy that tera- looks like the prefix "tetra-" meaning 4 without the third letter, so the name was continued with "peta" from "penta-".
The reciprocal of this prefix is femto-, from Danish "femten" meaning fifteen.
==Prefix conversion==
Peta- + Kilo- = Exa-
== Sources ==
== See also ==
Category:Prefixes
Category:SI prefixes