# When is 'de' needed after a number?

I saw this on social media:

Si tu pouvais avoir un million de dollars américains, mais que tu ne pourrais acheter que des choses commençant par la première lettre de ton prénom...qu'achèterais-tu ?

Why is de needed after million ? I was under the impression you did not need de after a number. I would say "J'ai deux chats," not "J'ai deux de chats."

• Cent dollars mais une centaine de dollars. [Det] [n] mais [det] [n] de [n]. Comme jlliagre le dit il est question de cardinal vs. substantif – Luke Sawczak Oct 16 '17 at 19:26

Si tu pouvais avoir un million dollars americains, mais ...

... is not correct.

In the case of ballpark figures such as "million", "dizaine", "trentaine" etc (as opposed to exact numbers such as "deux", "dix", "soixante" etc), you need to place "de" in between:

un million de chats

une dizaine de chats

une trentaine de chats {vs: trente chats}

des centaines de milliers de chats

• What if it's literally exactly one million ? – temporary_user_name Oct 16 '17 at 16:48
• @Aerovistae: de is required in any case after million, milliard, billion, etc. be it a ballpark or an exact figure. There's no way to tell the difference. – Stéphane Gimenez Oct 16 '17 at 16:53
• @Aerovistae Hi. I just used the term "ballpark/approximate figure" in comparison to exact numbers such as "dix". It doesn't matter whether the number you have in mind is exactly a million or a little over it; "de" cannot be dropped. Perhaps, there is a grammatical term for describing these numbers. – Con-gras-tue-les-chiens Oct 16 '17 at 16:58
• Million, milliard are substantives while deux, dix, trente are cardinal adjectives. – jlliagre Oct 16 '17 at 17:30
• Is this also true for deux million, trois million, etc? I would assume so. But not for deux million un. – temporary_user_name Oct 17 '17 at 18:21

There are two problems with million/milliard. On the one hand, they are measure nouns belonging to the same series as dizaine/centaine/millier but contrary to the latter, they act like mètre/litre:

• un mètre de tissu, un mètre cinquante de tissu
• un litre de lait, un litre vingt-cinq de lait
• un million d'euros, un million deux d'euros
• un millier d'euros, ?un millier deux d'euros?

On the other hand, they are cardinal building units (like dix/cent/mille) with the special property of demanding de marked nouns when they stand on the right margin:

• 999 999 pages, un million de pages, un million une pages
• deux milliards cent millions de pages, deux milliards cent millions une page

In the last examples above, they are not measure nouns because the first one is not understood as 2 000 000 100 x millions, and the second one runs into the same problem with the added quirk that the decimal parts have to be masculine.