1.183*10^11183*10¹¹ square km
The total area is $4\pi \sum_0^{100}(3000+120n)^2$.
We ask Wolfram Alpha (leaving out the 4$\pi$):
Now we just have to multiply the result by 4$\pi$:
4$\pi$ * 94172400009.417.240.000 = 1.183*10^11183*10¹¹ square km.
QED.