Number then a Capital word?

I am confused about the followings. Which one is correct?
4 months left.
4 Months loft.


Capitalisation is not affected by the word being preceded by a number. “month” is (almost always) a common noun that does not require a capital, in “4 months” or any other setting.

The only consideration, I suppose, is that proper (capitalised) nouns are rarely pluralised, so rarely follow a number. There are exceptions, such as “a tale of two Londons”, “the two Johns became friends”, etc.