I don't get your question but I think you mean XXVIII Clarify!
The number 28 is written as XXVIII in Roman numerals.
The number 1 is not a Roman numeral. The Roman numeral IX represents the number 9.
XXVIII is the number 28 in Roman numerals.
The Roman numerals "XXV" stand for the number 25.
Do you mean what do the Roman numerals XXVII stand for? If so then they stand for the number 27.
1562
XXVIII
VI are the Roman numrals for the number six.
The Roman numeral X represents the number 10
1000
50
1345