Q:

Scientific E Notation and conversion to decimal

I am working with satellite data and having fits understanding how to work with it because of the way the data is written (scientific E notation?). My math skills, unfortunately, are not where they should be for a programmer. I hope to find an answer here but I will give a small backstory to hopefully explain this better:
The data I am working on is lightning data, measured in units of 'Joules per Flash'. The  US National Weather Service can display this data on their systems, and there is a legend that shows which color corresponds to the level of energy: 

I managed to get ahold of the raw data, but it is in scientific notation and not on the 0-1500 scale as seen in the image. What is going on here?
For example, one value is $3.657199E-16$.
I figured I could convert that number to the nearest whole integer so I tried some converters online. (With my unfortunate math skills, this is what I resorted to).
I used  this calculator  and the result was a very tiny number in decimal form - $0.0000000000000003657199$

any number out of the data values I have are like this. Does anyone have any idea, or could give me guidance on how to convert this number? I don't understand why this could be. 

PS - If anyone finds this question to be unfitting or unsuitable to ask here, please tell me in the comments rather than downvote. I will happily delete the question if needed rather than lose reputation, I am just not sure where to ask but first, it would be helpful to know if the problem is math-related before moving on to other things.

A:

The conversion is very simple: simply shift the decimal dot 16 places to the left. Complete with zeroes if necessary. The meaning of the notation is
\begin{equation}
3.657199\times 10^{-16} = \frac{3.657199}{10^{16}}
\end{equation}
hence $3.657199$ divided by 10 million billions.
Of course with $6.02E23$ you would shift the dot 23 places to the right!
Edit I want to add that a value such as 3.65E-16 in numerical data may sometimes simply mean zero if it is the result of a computation in typical 64 bits floating precision. For example on my computer, if I compute
>>> 3 * 0.1 - 0.3
5.551115123125783e-17

This value simply means an error due to the limited precision of the computation. It doesn't have another meaning, let it be Joules or femto Joules!

