1 Gm (Gigameter) is equal to 9,999,999,999.999998 dm (Decimeter). To convert from Gigameter to Decimeter, multiply by 10,000,000,000 or divide by 0.0000000001.
Nine Billion Nine Hundred Ninety-Nine Million Nine Hundred Ninety-Nine Thousand Nine Hundred Ninety-Nine Point Nine Nine Nine Nine Nine Eight Decimeter