Manually specify starting value for Row_Number()

Just add the value to the result of row_number():

select 3258170 - 1 + row_number() over (order by (select NULL)) as idd

The order by clause of row_number() is specifying what column is used for the order by. By specifying a constant there, you are simply saying "everything has the same value for ordering purposes". It has nothing, nothing at all to do with the first value chosen.

To avoid confusion, I replaced the constant value with NULL. In SQL Server, I have observed that this assigns a sequential number without actually sorting the rows -- an observed performance advantage, but not one that I've seen documented, so we can't depend on it.

I feel this is easier

ROW_NUMBER() OVER(ORDER BY Field) - 1 AS FieldAlias (To start from 0)
ROW_NUMBER() OVER(ORDER BY Field) + 3258169 AS FieldAlias (To start from 3258170)