I know how to declare a unit using siunitx
\DeclareSIUnit[number-unit-product = \,]\hello{hello}
which just gives the written text hello. I also can combine it with the usual syntax like
\DeclareSIUnit[number-unit-product = \,]\hello{\milli hello}
but how can I write a number inside a newly defined unit?
\DeclareSIUnit[number-unit-product = \,]\hello{1e6 hello}
for example?
\SI{2}{\hello}– egreg Feb 16 '17 at 17:25