From series of numbers 12300 to 12399,,three facts:
1. First number to have train allotted in this series: 12301 hwh ndls rajdhani exp via gaya.
2. Last number to have train allotted in this series of numbers: 12398 ndls gaya mahabodhi Exp
3. Only palindrome number to have train allotted in this series: 12321 howrah cstm mail via ald.