Decimal precision - how to have 18 decimals?

[tototototototototo]

Hello, I am inputting numbers that have 18 decimals. For example :
0.041345058938493747

Default settings seem to round up this number and save it as:
0.0413450589384938

I have tried to use the Format… dialog to increase precision, but it still rounds it up to 16 decimals:
0.041345058938493800

So…? How do I increase precision? Thanks in advance!!!

[cloph]

You can’t. LibreOffice uses IEEE 754 representation of the numbers, and that just doesn’t offer that level of precision.

see also column has been defined as a "Decimal" type, the max. length is 19 characters (with 15 decimal places).

and general description of the way precision works in IEEE 754 here:

Numeric precision in Microsoft Excel

If you want to store the values in a spreadsheet, you have to do so as text (enter them by prefixing them with a single quotation mark, that will force the input to text)