The radius of a proton is approximately 10-15 meters, which gives it a volume of: 4π(R3)/3 = 4.19x10-30 m3.
The radius of the electron's orbit around the proton is approximately
5.29 x 10-11 meters, which defines the radius of the atom. So the entire volume of the atom is about
4π(R3)/3 = 1.17x10-20m3.
(1.17x10-20 m3) / (4.19x10-30 m3) = 2.80x109.
The atom is 2.80x109, or 2,800,000,000, times larger than its nucleus; the volume of the electron is negligible. There's a number that gives you an appreciation for how empty an atom actually is! It's about the same as the ratio of the volume of a pea to that of a large, two-story house.