Huge amount of work stopping no one company rising (9)

I believe the answer is:

octillion

I'm a little stuck... Click here to teach me more about this clue!

'huge amount' is the definition.
The definition suggests a singular noun which matches the answer.

'work stopping no one company rising' is the wordplay.
'work' becomes 'till' (to till is to work the land).
'stopping' indicates putting letters inside (stopping can mean blocking a gap).
'one' becomes 'i' (Roman numeral).
'company' becomes 'co' (abbreviation).
'rising' is a reversal indicator (going up in a down clue).
'no'+'i'+'co'='noico'
'noico' written backwards gives 'ocion'.
'till' inserted inside 'ocion' is 'OCTILLION'.

'of' acts as a link.

Can you help me to learn more?

(Another definition for octillion that I've seen is " Large number".)

I've seen this clue in The Guardian.

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