copywriting - What is an alternative way to display a very large number?

In my application I have a text field that should display numbers (representing money) ranging from 0 to 999 trillion.

The users of my application are the general public, so displaying a scientific notation such as "1.021356e16" is not acceptable.

What formatting options do I have?

I wouldn't want to display 999,999,999,999,999.00. It's not really readable and would require a large text field, which would waste a lot of space for the majority cases which are lower than 100M.

Answer

I think (a) * 10^x, e.g. 1.02 * 10^16, is easier for people to read than scientific notation.

Even easier would be to just use the abbreviations for the powers of 1000:

107K
44M
392B
602T