centillionth

cen·til·lion

 (sĕn-tĭl′yən)
n.
1. The cardinal number equal to 10303.
2. Chiefly British The cardinal number equal to 10600.

[Latin centum, hundred; see dekm̥ in Indo-European roots + (m)illion.]

cen·til′lion adj.
cen·til′lionth adj.adv. & n.

centillionth

(sɛnˈtɪljənθ)
n
(in Britain and Germany) a number equal to 10–600(in the US, Canada, and France) a number equal to 10–303