Yes, the capital letter N has rotational symmetry but no lines of symmetry:
S
None.
None.
None.
Two.
The letter "O" has rotational symmetry, as it looks the same when rotated 180 degrees.
2
H
In the good old days (when I was at school and was taught about rotational symmetry) it had one, but the modern definition is to say it has none.
it has order two (180 degrees)
There are 10 letters in the alphabet that achieve rotational symmetry when displayed in their capital form. These letters: A, H, I, M, O, U, V, W, X, and Y.