There're 8 letters in the word, sounting the repeating letter "N".

\(\displaystyle\frac{{{n}!}}{{{\left({\underset{{{1}}}{{{r}}}}!\right)}{\left({\underset{{{2}}}{{{r}}}}!\right)}\ldots{\left({\underset{{{k}}}{{{r}}}}!\right)}}}\)

Substitute:

\(\displaystyle\frac{{{8}!}}{{{2}!}}=\frac{{40320}}{{2}}={20160}\)

There're 20160 ways.

\(\displaystyle\frac{{{n}!}}{{{\left({\underset{{{1}}}{{{r}}}}!\right)}{\left({\underset{{{2}}}{{{r}}}}!\right)}\ldots{\left({\underset{{{k}}}{{{r}}}}!\right)}}}\)

Substitute:

\(\displaystyle\frac{{{8}!}}{{{2}!}}=\frac{{40320}}{{2}}={20160}\)

There're 20160 ways.