Answer
$1.39\text{ g/cm}^3$
Work Step by Step
We cakculate the volume:
$V=\frac{4\pi}{3}(7\times 10^{10})^3\approx 1.436\times 10^{33}\text{ cm}^3$
Then we determine the density:
$\text{Density}=\frac{2\times 10^{33}\text{ g}}{1.436\times 10^{33}\text{ cm}^3}\approx 1.39\text{ g/cm}^3$
