What is the average mass in grams of one mole - atom - liter potassium?

Potassium in grams:

• per mole: 39.10 gram/mole
• per atom: 39.10 (a.m.u./atom) * 1.6605.10-24(g/a.m.u.) = 64.93 *10-24 gram
• per Liter: 0.860 kg/L = 860 gram/L (as solid at STP)