14 is a natural number, which is the set { 1, 2, 3, 4, ... }.
14 is a whole number, which is the set { 0, 1, 2, 3, 4, ... }.
14 is a interger, which is the set { ..., -4, -3, -2, -1, 0, 1, 2, 3, 4, ... }.
14 is a rational number, which is the set of all fractions of intergers, so long as the denominator isn't 0. 14 = 14/1.
14 is a real number, because you can place it on the real number line.