2005
In modern day notation of Roman numerals MCMLXIII is the equivalent of 1963 but the ancient Romans would have probably expressed it quite differently
It is: 205 = CCV in Roman numerals
We do use Roman numerals today. For example, Roman numerals are often found in making outlines; to label book chapters; to label the frontmatter (pages) in books.
The Roman numerals for 64 are ILXV (65-1) or LXIIII (64) and they are not LXIV. So your question is: What is the cube root of LXIIII in Arabic numerals? The answer is 4 which is IIII or IV in Roman numerals.
The Roman numerals of CCX are the equivalent of 210 in Hindu-Arabic numerals.
210
It is: 210 = CCX
Exactly as in the question but if you mean in Roman numerals they are CDXXXVI, DX and CCX respevtively
They are: CDXXXVI, DX and CCX respectively
It is: (VII)CCX = 1000*7+210 = 7210
It is: (M)CCX which means 1000*1000+210 = 1,000,210
They are: (V)CCX which means 1000*5+200+10 = 5210
It is: CCX = 210
2x3x5x7 = 210 II*III*V*VII = CCX
"120" in Roman numerals is "CXX".
Those Roman Numerals mean 1991.