Yocto (Units Package Symbol)

Yocto is the SI unit prefix denoting 10 -24.

Yotta (Units Package Symbol)

Yotta is the SI unit prefix denoting 10^24.

Zepto (Units Package Symbol)

Zepto is the SI unit prefix denoting 10 -21.

Zetta (Units Package Symbol)

Zetta is the SI unit prefix denoting 10^21.

Scientific & Technical Data (Mathematica Guide)

Mathematica has immedate built-in access to extensive scientific and technical data—all carefully curated and updated at Wolfram Research.

NaN (Computer Arithmetic Package Symbol)

NaN is the symbol used by the functions in the Computer Arithmetic Package to represent a nonrepresentable number.

J (Quaternions Package Symbol)

J represents a quaternion unit with J^2 == -1.

Quaternions (Quaternions Package Symbol)

Quaternions is an option for PrimeQ which specifies whether factorization should be done over the quaternions.

UnitQuaternions (Quaternions Package Symbol)

UnitQuaternions gives a list of the 24 units in the ring of integer quaternions.

$VersionNumber (Built-in Mathematica Symbol)

$VersionNumber is a real number which gives the current Mathematica kernel version number, and increases in successive versions.