Nat.totient_eq_prod_factorization

∀ {n : ℕ}, n ≠ 0 → n.totient = n.factorization.prod fun p k => p ^ (k - 1) * (p - 1)

Euler's product formula for the totient function.

Defined in: Mathlib.Data.Nat.Totient
Cited by: 2 results in Mathlib
Foundations: Depth 97 from the axioms · uses propext, Classical.choice, Quot.sound

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