Convert from palmo [Portuguese] to zeptometer

Unit Definition (palmo [Portuguese])
The palmo is a traditional unit of distance in Spain and Portugal. The Portuguese palmo equals 0.1 braça or about 22.0 centimeters (8.66 inches). These units are based on the width of a person's outstretched hand, from the tip of the thumb to the tip of the little finger, a definition identical to that of the English span.

Unit Definition (zeptometer)
The zeptometre (or zeptometer), symbol: zm, is an SI unit of metric length measurement. 1 zeptometre is 1e-21 metres, which is a very small distance