How to disable "E" symbol in large digits?

Hi!

I'm creating Bytes Calculator in Visual Basic 2012.
I'm beginner on platform .net, before I was using VB6.

In calculator is possible to convert e.g. PB to B.
So large symbols displays:
1 PB = 1,12589990684262E+15 B

HOW TO DISABLE SYMBOL "E" TO SHOW NUMBER AS IS?

Many many thanks for every help, reply or comments.

Miro