difficulty – Isn’t Bitcoin’s hash target supposed to be a multiple of 2?

From Bitcoin’s whitepaper I’ve gathered that the hash of a block must start with a certain number of zeroes. And that this number of zeroes is adjusted every 2 weeks. Consequently the hash target is a multiple of two.

Requiring an extra zero for the hash function will divide the hash target by 2.

With that being said, in another question on the exchange (How is difficulty calculated?) it appears that the difficulty can be multiplied by fractions (e.g. 40%).

Does that mean that the hash targets aren’t necessarily multiples of 2? Or is the target rounded to the nearest multiple of 2?