Convert from hectometer to zettameter

Unit Definition (hectometer)
A hectometre (American spelling: hectometer, symbol: hm) is a measurement of distance equal to 100 metres. This measure is rarely used and is included mostly for completeness, since usage of the SI prefix hecto is no longer recommended.

Unit Definition (zettameter)
The zettametre (or zettameter), symbol: Zm, is an SI metric unit of length. 1 zettametre is equal to 1e+21 metres, a very large distance. Not to be confused with a zeptometre.