want to know maximum value a decimal can store or propagate

[somesh2suma]

Hi All

i want to know the maximum value or digits that a decimal datatype can store and propagate to the next stage.

For example: if decimal(20,0) is declared and assigned with 999999999999999999 value it will give a negative value after moving to the next stage.

So would like to know if any rule to calculate the maximum value.