The word order Numeral Noun is allowed in the unmarked case, that is, in stylistically unmarked contexts with no special focus on any of the constituents. See Dryer (2008).

<br><br>An example is English <i>three guitars</i>.

<br><br><b>Reference</b><br>
Dryer, Matthew S. 2008. Order of Numeral and Noun.
In Haspelmath et al. (2008), chapter 89. Available online at <a href="http://wals.info/feature/89">http://wals.info/feature/89</a href>. 
Accessed on 2008-12-29.

