|≈||approximately equal to|
|digits||indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …)|
An attometer is a unit of length, a combination of the metric prefix atto (symbol a) and the SI unit of length meter (symbol m), equal to 10−18 meter or 1.0E-18 meter and its symbol is am. Plural name is attometers.
Petameter or petametre is equal to 1015 meters (unit of length), comes from a combination of the metric prefix peta (P) and the SI unit of length meter (m). Plural name is petameters.