  We report here oscillator strengths, transition rates, branching ratios and
lifetimes due to allowed transitions in potassium (K) atom. We evaluate
electric dipole (E1) amplitudes using an all order relativistic many-body
perturbation method. The obtained results are compared with previously
available experimental and theoretical studies. Using the E1 matrix elements
mentioned above and estimated from the lifetimes of the 4P states, we determine
precise values of static and dynamic polarizabilities for the first five
low-lying states in the considered atom. The static polarizabilities of the
ground and 4P states in the present work are more precise than the available
measurements in these states. Only the present work employs relativistic theory
to evaluate polarizabilities in the 3D states for which no experimental results
are known to compare with. We also reexamine "magic wavelengths" for the
$4P_{1/2} \rightarrow 4S$ and $4P_{3/2} \rightarrow 4S$ transitions due to the
linearly polarized light which are useful to perform state-insensitive trapping
of K atoms.
