Squarefree integer

An integer $𝑛 \in ℤ$ is said to be squarefree if it not divisible by any square number other than 1, num i.e.

(\forall 𝑘 \in ℕ) [𝑘 2 ∣ 𝑛 ⟹ 𝑘 = 1]