[avoid3d]

You lost 6 orders of magnitude to this IMHO:

5610 million km^3 = 5.61 * 10^3 * 10^6 km^3 = 5.61 * 10^9 km^3 = 5.61 * 10^9 * 10^9 m^3 = 5.61 * 10^18 m^3

But you said the resulting volume was = 5.61 * 10^12 m^3.

I think you forgot that it was 5610 million km^3.

[jacquesm]

Ah! I knew there was something terribly wrong there somewhere (and probably that's not the only thing). Thank you very much, I'll edit the comment to fix it.