(transitive) To find all the factors of (a number or other mathematical object) (the objects that divide it evenly).

(transitive) to reduce an integer to its set of prime factors.

(number theory) A factor of a given integer which is also a prime number.

(physics) The ratio of the RMS value to the absolute mean of a sinusoidal wave (especially to that of an alternating current)

(idiomatic) An unknown or hard-to-define influence; a factor with unknown or unforeseeable consequences. / (idiomatic) A special talent, ability or quality or its indefinable cause.

An antigen of the Rhesus system; understood unless otherwise specified to refer to Rhesus factor D (RhD), which appears on the surface of the red blood cells of most (85%) humans. An incompatibility between the Rh-blood types of a mother and her baby may cause serious disease for the baby.

Alternative spelling of X factor

Alternative spelling of X factor

Alternative spelling of X factor

plural of factoid