Do you put any hyphens when you spell out numbers? Like two thousand-two, or two-thousand-two?
Hyphens should be used between digits for numbers between twenty-one and ninety-nine.
Otherwise hyphens are either not to be used or are optional.
Out side the range 21 to 99 (where they are always required) the rules for their usage seems regional.
In some places (England?), they are forbidden in proper usage.
In others (United States), they may be used at the author's discretion.