QuaternionQ[q] gives True if q is a quaternion and False otherwise.

RightAssociates[q] gives a list of the 24 right associates of the quaternion q.

ScalarQ[q] gives True if q is a real numeric quantity and False otherwise.

ToQuaternion[q] transforms q into a Quaternion object if possible.

UnitQuaternionQ[q] gives True if q is a unit quaternion and False otherwise.

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

Atto is the SI unit prefix denoting 10 -18.

BakersDozen is a unit multiplier.

Dozen is a unit multiplier.

Gross is a unit multiplier.