KnowraEuler characteristicLinked fromLinked fromThe 37 pages that link to Euler characteristic, each with the reason it gives.All 37Broader topic 1Related 32Narrower topic 2Compared with 2Euler's polyhedron formulaNarrower topic: The value two is the sphere's Euler characteristic, the deeper invariant behind the formula.Hopf conjecture (Euler characteristic)Narrower topic: Its sign is the quantity the conjecture predicts.