  We show that the right ideal of a Novikov algebra generated by the square of
a right nilpotent subalgebra is nilpotent. We also prove that a $G$-graded
Novikov algebra $N$ over a field $K$ with solvable $0$-component $N_0$ is
solvable, where $G$ is a finite additive abelean group and the characteristic
of $K$ does not divide the order of the group $G$. We also show that any
Novikov algebra $N$ with a finite solvable group of automorphisms $G$ is
solvable if the algebra of invariants $N^G$ is solvable.
