Oracle 10g database table with a column having data type Number(20) stores 18 digits organization code. When this data is retrieved in SQL*Plus or Toad it is displayed in scientific notation format. The display format can be changed from scientific notation format to number format. But, for some reason the number rounds up. For example if the organization code stored in the database is 541200659999999999 when it is retrieved from database it is found to be 541200660000000000. Is there any one who knows why Oracle does this? Thank you in advance for your help.