To be exact, it should be 십일만 육천 원. The language standards specify we space it at every four digits (만, 억, 조, ...).
Example: 1,234,567,899 원 => 십이억 삼천사백오십육만 칠천팔백구십구 원.
But such spacing is not that important since no one writes it that way. You just need to be able to read it correctly.