It is: 900 = CM
CCCLXXVIII
DCXLI
MMX
IX
MCMLXXVII
Letters are not numbers. Not all letters in the alphabet represent Roman numerals though some letters do.
C.m.
3210 = MMMCCX in Roman numerals which are expressed in letters
The roman numeric way to write 46 is XLVI.
In Roman letters, it is KRASNY
2 = II
XXXIX= 39