Peta

Peta (symbol: P) is a prefix in the SI system of units denoting 10¹⁵, or 1 000 000 000 000 000.

In computer science peta can sometimes mean 1 125 899 906 842 620 (1024⁵ or 2⁵⁰), instead of 1 000 000 000 000 000, especially when used to prefix the byte, giving a petabyte.