The Product

In scientific notation, it's

5.8 x  10¹⁰    

 But  since 5.8 is close to 6 and you want an estimate, we can write....   ≈ 6 x 10¹⁰        

I don't quite understand what you want. If you want the power of 10 that will give you 58,000,000,000, then that is very easy:

10^x=58,000,000,000, we take the logs of both sides,

xLog(10)=Log(58,000,000,000)

x=10.763428....I hope that's what you want.