On distance{based graph invariants

Let G be a simple connected graph of order n with m edges and diameter d. Let W, WW, H, and RCW be the Wiener index, hyper-Wiener index, Harary index, and reciprocal complementary Wiener index of G. The multiplicative version of Wiener index (π-index) is equal to the product of the distances between all pairs of vertices. We compare H and RCW. For bipartite graph of order n > 5, we prove that π > 2WW. In any connected graph, if d ≥ 4 and m ≤ 285W-6624 287 , then π ≥ 2WW. Some additional relations between W, WW, H, and RCW are also obtained.