The romans themselves didn’t have a number Zero , what they did have was a blank space, They got that from the Babylonians. The actual concept of zero as a numeric symbol comes out of India
The concept of zero arrived centuries later when the Arabic the concept of Zero did not come about until the 14th Century. It radically changed mathematics..The word nulla (the Latin word meaning “none”) was used by medieval computists in lieu of 0. Dionysius Exiguus was known to use nulla alongside Roman numerals in 525. About 725, Bede or one of his colleagues used the letter N, the initial of nulla, in a table of epacts, all written in Roman numerals.