Planck momentum is the unit of momentum in the system of natural units known as Planck units. It has no commonly used symbol of its own, but can be denoted by, where is the Planck mass and is the speed of light in a vacuum. Then where is the reduced Planck's constant, is the Planck length, is the gravitational constant. In SI units Planck momentum is $\approx 6.5 kg m/s$.
Planck Momentum