Ninety-one million, two hundred, twenty-eight thousand, four hundred, forty-four.

If you are just talking about any number, then Tim's answer is good and completely correct. The one exception might be with a phone number or postal zip code. If I had a phone number of 567-3444, I might say it as: five six seven three triple-four. 567-3004 five six seven three double-oh four [Note that in English, sometimes a zero is spoken as the letter 'O' - a little confusing, I'll admit.] Once you get to four digits repeated, you would probably not hear 'quadruple-x'. Note that you could also say the repeated digits individually.

91228444 It will be less confusing if you leave out the double and the triple. Say 91 million, two hundred twenty eight thousand, four hundred forty four.

I've been to China, so I'm guessing that your number is a non-mobile phone number. There are a couple of different ways I would say it. The first one would be to say it in groups of four, as in "nine one two two, eight four four four". Some people might miss one of the repeated fours, and ask you to repeat it. This brings me to the second way, using double-digit words: "ninety-one, twenty-two, eighty-four, forty-four". This makes the number combinations more clear to the listener, and that's especially important if the person is cute and you want him/her to remember your number. Personally, I use a combination of these two styles: "nine one two two, eighty-four, forty-four". The repeated fours are the reason I would choose the double-digit words on the second half. In the future, you want to change your question form. Don't ask "How to say.....?" or "How to do ....?". These are not full questions. It is better to ask "How do I say ...?", "How can I ....?, or "How do you ...?" The words 'how to' are actually used as part of a noun phrase, so they can be in the subject of a sentence: "How to write poetry was the topic of his lecture". More commonly, you will use them as part of the predicate, but they must follow an active verb: "Can you tell me how to ...?", "Would you show me how to ...?" "Did you learn how to ...?".

91228444 : If a numeric digit (like currency) you can say ** Ninety one million two eighty four thousand and four hundred and forty four ** (In India) 9 Crores Twelve lakhs twenty eight thousand four hundred and forty four If a phone number ** Nine One Double-two Eight Triple-four ** Or each number individually