Differentiate between the factor (s) that affect inertia and momentum.

Inertia relates directly to an object's mass. It is its inherent property and expresses how much force is needed to bring the object to a certain level of acceleration. It is the sole factor.

Momentum relates proportionally to two factors: mass and velocity. As such, momentum is not an inherent property of an object but a measure dependent on it current velocity, in addition to its mass.