21 in Roman numerals is XXI. 1 in Roman numerals is I. 90 in Roman numerals is XC. So, 21 1 90 would be XXI I XC in Roman numerals.
x = 10 i = 1 xxi = 21
21
XXI is the number 21 in Roman numerals.
ix is 9, and xxi is 21 In Roman Numerals it is IX for 9 and XXI for 21. You see the letters in Roman Numerals have always been upper case (Capitals) for some reason.
December 21, 2011 is written as "XII XXI MMXI" in Roman numerals.
V-xxi-ixi-vii viImproved Answer:-In today's notation of Roman numerals it is: V-XXI-MCMLXXVI
May 21, 1995 in roman numerals is written as XXI V MCMLXXXV.
September 21, 2013 can be written in Roman numerals as "XXI-IX-MMXIII".
I/XXI/LXXXIX
XXI
21