How many ways can you say 15409

You can "say" 15409 in potentially infinite ways:

15,000 + 409

15,001 + 408

15,002 + 407

etc.

To write 15,409 in expanded form, just take each digit and write the following ones as zeroes, adding them together like so:

10,000 + 5,000 + 400 + 9

We leave out the "00" because that doesn't have any real value.

The number is "fifteen thousand four hundred nine".

In addition to my normal speech, I can say it in maybe ten different

regional dialects and foreign accents, but none of them really well.

I can also say it in four foreign languages that are not English.