When we spell in Italian, we can say doppia ci etc.. for double letters. Can one also do this for numbers i.e. telephone numbers ? Can I say my number is due, doppia uno, sei etc... ? Thanks. Paul
No, we normally don't do this with telephone numbers. (By the way, I think it's not so common even when spelling words.)
However, we often say numbers in groups of two:
Trentanove, settantaquattro, ventuno, diciassette.
Spelling each figure separately is correct too, of course.