[kenko]

"The characters or substrings that make up a string stand on their own. In fact, it's pretty hard to differentiate a string from an array of characters."

It's difficult to differentiate a number from an ordered n-tuple of bits, but that doesn't make storing the number 123 storing an array.

I took the parent post's point to be clear: it isn't whether you can look at something as, in some sense, an array, it's whether you treat it as an atomic value. That's generally what you do with numbers: you update the whole number, not the third bit. And it's likely what you do with strings---even if you just want to change one character, you update the whole string, not the third character.

Likewise, if you want to store a complex number as a 2-tuple, you could treat that as an atomic data type even though it consists of two elements by always operating on the pair*. That's the respect in which it "stands on its own"---you don't peer inside.