1 h/m^2 (Hour/Meter^2) is equal to 3,599,999,999.999997 s/km^2 (Second/Kilometer^2). To convert from Hour/Meter^2 to Second/Kilometer^2, multiply by 3,599,999,999.9999976 or divide by 0.00000000027777777777777797.
Three Billion Five Hundred Ninety-Nine Million Nine Hundred Ninety-Nine Thousand Nine Hundred Ninety-Nine Point Nine Nine Nine Nine Nine Seven Second/Kilometer^2