Convert from gigameter to attometer

Unit Definition (gigameter)
The Gigameter (or Gigametre) a metric unit of distance equal to one million kilometers or about 621,371.2 miles. It is seldom used, but this unit would be a good yardstick for the inner Solar System: the distance from the earth to the sun is about 149.60 gigameters.

Unit Definition (attometer)
An Attometer (or attometre) is equal to one quintillionth of a meter, or sometimes denoted as 10e-18 meters. The origin of the prefix is atten, the word for 18 in Danish and Norwegian.