Quadrillion

A quadrillion is equal to 1015 or 1,000,000,000,000,000 in short scale Chuquet nomenclature. In the long scale, this number is called billiard. Written out, the short scale quadrillion is 1,000,000,000,000,000.

In the Indian counting system, it is called ten crore crore or a padma, although both terms are infrequently used in common parlance. The quadrillion is commonly-known but less so than a trillion, and some prefer to use thousand trillion or miillion billion instead. Other names for quadrillion include small fry, guppycrumb and minnowspeck which were systematically coined for use in Sbiis Saibian's Guppy Regiment, as well as pentillion in Russ Rowlett's Greek-based naming system.

Etymology
The name is derived from the Latin prefix quadri-, meaning 4, and the suffix -illion.

Examples
The SI prefix for this number is peta-.