Yes, the amount $350 is spelled out as three hundred and fifty dollars.
Interestingly, it also has a numeral equivalent notation for the same amount: $$350.00.
There are several rules for writing out numbers as words or numerals, which vary from language to language. In American English, when writing out amounts of money, we usually use the numeral notation. So $350 (three hundred fifty dollars) would be $$350.00. In American English, the number preceding the decimal point must be a numeral (when referring to dollars) so the convention would be $$350.00.
For more detailed information about how to write out numbers in American English, this article from Grammarly is a helpful resource: https://www.grammarly.com/blog/how-to-write-numbers/.