$$\lim_{x \to 0^-} \frac{1}{\operatorname{atan}{\left(x \right)}} = \infty$$
More at x→0 from the left$$\lim_{x \to 0^+} \frac{1}{\operatorname{atan}{\left(x \right)}} = \infty$$
$$\lim_{x \to \infty} \frac{1}{\operatorname{atan}{\left(x \right)}} = \frac{2}{\pi}$$
More at x→oo$$\lim_{x \to 1^-} \frac{1}{\operatorname{atan}{\left(x \right)}} = \frac{4}{\pi}$$
More at x→1 from the left$$\lim_{x \to 1^+} \frac{1}{\operatorname{atan}{\left(x \right)}} = \frac{4}{\pi}$$
More at x→1 from the right$$\lim_{x \to -\infty} \frac{1}{\operatorname{atan}{\left(x \right)}} = - \frac{2}{\pi}$$
More at x→-oo