3,5 10^-10 Gm

Also, notice that ypu can round it up a bit…

And, who meassures his dick… you just need an honest aproximation.

Exemple: “my dick? You mean from the root? I think it’s just a fraction of a gigameter…” which is a 100% honest and humble response.

Edit: one can also use astronomic units… 1 AU =~ 150 Gm