Ordinal number; the item in position 1 followed by 33 zeros (in short scale) or 1 followed by 60 zeros (in long scale) in a sequence.
From 'decillion' plus the ordinal suffix '-th.' This ordinal form emerged in mathematical and scientific texts wherever decillionth subdivisions or sequences needed to be numbered.
If you could divide something into a decillionth of itself, each piece would be unfathomably tiny—at that scale, you've entered quantum territory where the very concept of 'pieces' breaks down. It's a number language created long before physics showed us why such sizes don't actually exist in reality.
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