How much larger is the solar system than earth?
Earth's radius is 6371 km but for the sake of convenience I will take its diameter 12,742 km as its size.
What we have farthest in Solar system is Oort Cloud, at a distance of 100,000 Astronomical Unit.
As an Astronomical Unit is approx. 149,597,871 km, you can say solar system is
The radius of the Earth in AU unit is 4.24 E-05. Using formula for space of a sphere, and assuming that heliosphere has radius 100 AU, the ratio is 1. E+06 / 7.6 E-14 = 1.3 E+19.