Given an undirected graph $G = (V,E)$, what is the clique number $\omega(G)$ given $|E|$, i.e., the size of the largest clique in a graph with $|E|$ edges.
I think this is doable after realizing that the number of edges in a clique is equal to the triangular number: $$|E(K_k)| = \frac{1}{2}k(k-1).$$
I am looking for a closed formula.