Nowadays it is DXLV but the ancient Romans would have wrote it out quite differently
Sorry, that's not a valid Roman number (DXLV would be = 545)
In today's modern notation of Roman numerals it is now DXLV but the ancient Romans probably notated it quite differently.
In Roman numerals the number 77 is written as LXXVII.
1900 is written in Roman numerals as MCM.
The number 2100 written in Roman numerals is MMC
887 in Roman numerals is DCCCLXXXVII
4000 is written as MMMM.
30.12.1997 is written in roman numerals as XXX.XII.MCMXCVII
1750 in Roman numerals is: MDCCL
1,314 written in Roman numerals is MCCCXIV
Roman numerals written in block capitals.
9998 in Roman numerals is written as I̅X̅X̅C̅ MCMXCVIII.