Prime powers and factorizations #
This file deals with factorizations of prime powers.
theorem
IsPrimePow.minFac_pow_factorization_eq
{n : ℕ}
(hn : IsPrimePow n)
:
Nat.minFac n ^ (Nat.factorization n) (Nat.minFac n) = n
theorem
isPrimePow_of_minFac_pow_factorization_eq
{n : ℕ}
(h : Nat.minFac n ^ (Nat.factorization n) (Nat.minFac n) = n)
(hn : n ≠ 1)
:
theorem
isPrimePow_iff_minFac_pow_factorization_eq
{n : ℕ}
(hn : n ≠ 1)
:
IsPrimePow n ↔ Nat.minFac n ^ (Nat.factorization n) (Nat.minFac n) = n
theorem
isPrimePow_iff_factorization_eq_single
{n : ℕ}
:
IsPrimePow n ↔ ∃ (p : ℕ) (k : ℕ), 0 < k ∧ Nat.factorization n = Finsupp.single p k
theorem
exists_ord_compl_eq_one_iff_isPrimePow
{n : ℕ}
(hn : n ≠ 1)
:
IsPrimePow n ↔ ∃ (p : ℕ), Nat.Prime p ∧ n / p ^ (Nat.factorization n) p = 1
An equivalent definition for prime powers: n
is a prime power iff there is a unique prime
dividing it.
theorem
Nat.Coprime.isPrimePow_dvd_mul
{n : ℕ}
{a : ℕ}
{b : ℕ}
(hab : Nat.Coprime a b)
(hn : IsPrimePow n)
:
theorem
Nat.mul_divisors_filter_prime_pow
{a : ℕ}
{b : ℕ}
(hab : Nat.Coprime a b)
:
Finset.filter IsPrimePow (Nat.divisors (a * b)) = Finset.filter IsPrimePow (Nat.divisors a ∪ Nat.divisors b)