Let R be a commutative ring with unity. The prime ideal sum graph
PIS(R) of the ring R is the simple undirected graph whose vertex set
is the set of all nonzero proper ideals of R and two distinct vertices I
and J are adjacent if and only if I+J is a prime ideal of R. In this
paper, we classify non-local commutative rings R such that PIS(R) is
of crosscap at most two. We prove that there does not exist a finite non-local
commutative ring whose prime ideal sum graph is projective planar. Further, we
classify non-local commutative rings of genus one prime ideal sum graphs.
Moreover, we classify finite non-local commutative rings for which the prime
ideal sum graph is split graph, threshold graph, cograph, cactus graph and
unicyclic, respectively