Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Season # | Series # | Episode title | Original air date | Nick prod. # |
| --- | --- | --- | --- | --- |
| 1.0 | 123.0 | " B2K " | September 21, 2002 | 827 |
| 3.0 | 125.0 | " Yasmeen " | October5,2002 | 829 |
| 4.0 | 126.0 | " Jeffrey Licon / Jennifer Love Hewitt " | October12,2002 | 830 |
| 5.0 | 127.0 | " Justin Timberlake / Aaron Carter " | October19,2002 | 831 |
| 6.0 | 128.0 | " Tom Green / Avril Lavigne " | October26,2002 | 832 |
| 7.0 | 129.0 | " 3LW " | November2,2002 | 833 |
| 8.0 | 130.0 | " Nick Carter / BBMak " | November9,2002 | 834 |
| 9.0 | 131.0 | "Harry Bladder Special" | November16,2002 | Special |
| 10.0 | 132.0 | " Justincase / Britney Spears " | November23,2002 | 835 |
| 11.0 | 133.0 | " Nick Cannon / Monica " | January25,2003 | 836 |
| 12.0 | 134.0 | " Debbie Gibson " | February1,2003 | 837 |
| 13.0 | 135.0 | " Matthew Lillard / O-Town " | February8,2003 | 838 |
| 14.0 | 136.0 | " Tom Green / No Secrets " | February15,2003 | 839 |
Question:
What is the series # on airdate September 21, 2002?
Answer:
123.0