a (the) rapidly growing number of

A quote from The Economist (Higher education: The attack of the MOOCs):

The new money should allow Coursera to build on any advantage it has from being a first mover among a rapidly growing number of MOOC providers.

I'd like to know, would it be OK to change it to

The new money should allow Coursera to build on any advantage it has from being a first mover among the rapidly growing number of MOOC providers.

P.S. Does the indefinite article before "first mover" indicate that Coursera is "one of the first movers", but not the very first?

• a number of providers means many providers. a large number of, a growing number of,.... also means many. On the other hand, the number of the providers means how many of the providers. Therefore, a rapidly growing number of providers is correct in the given context. Commented Jul 28, 2013 at 14:08
• I'm afraid I don't catch the difference, Jay. "..the number of MOOC providers" means "..how many of MOOC providers"? Commented Jul 28, 2013 at 16:12
• @CopperKettle It means if you have 10 MOOC providers, the number of MOOC providers is 10. It refers to the number, not the (group of) providers. A number = many, not specifying how many (1,2,3,...) providers there are.
– user1513
Commented Jul 29, 2013 at 5:25
• Thanks a million, Fantaiser. Gotta jot this down somewhere and jury-rig some self test on this distinction. "A first mover.. among the quantity of providers" should sound crazy to the native speaker. Commented Jul 29, 2013 at 11:06

"A number of" means several.

We have discussed the matter on a number of occasions.

It could also mean some.

A number of problems have arisen.

In your case, it means several. The author is using "a number of" because is trying to give state two facts:

• There are several MOOC providers that did something
• The number of MOOC providers doing that is rapidly growing
• Thanks, Kiamlauno! I know of the "a number of"-"several" equivalence. Would a definite article really wreck the "a number of" construct so hard that it would no longer mean "a small group (=several) of" and become illogical? Commented Jul 29, 2013 at 13:14
• The idiomatic expression is "a number of" not "the number of." Replace a with the in both the example sentences I shown, and the meaning changes. (Whenever a native speaker would still understand the sentences is another matter.) You could say "I cannot count the number of times I told you no." but that has a different meaning. Commented Jul 29, 2013 at 13:16
• I wonder if the intercalating "rapidly growing" combo hadn't broken the idiom in the first place. Maybe here the author does not intend to use the idiom but merely means "a rapidly growing group of.." Google Books finds instances of "among the growing number of..", such as: 'Ill health among the growing number of younger adults places a very significant burden on health and social care.' (2012, Anita Fatchett, Social Policy for Nurses). Commented Jul 29, 2013 at 13:25