Just one. (1)
it depends on the size of the cage.
1+2+4+8=15 There can't be half of a hamster. Start with the smallest cage with the smallest amount possible:1
Many people who have owned hamsters say that, that kind of cage is dangerous for hamsters, even dwarf hamsters. Also, there are many ways that a hamster can be killed in that cage. It's a death trap for a hamster or anything else. They may look cute and colorful but they are NOT good for any type of small rodent.
You can keep a maximum of two dwarf hamsters in one cage to prevent territorial issues and ensure they have enough space to move around comfortably. It's important to provide plenty of hiding spots, toys, and multiple food and water sources to reduce competition and stress among the hamsters. Regular monitoring of their behavior and health is essential when housing multiple hamsters together.
It is recommended to have only one hamster per cage to prevent territorial disputes and fighting. Hamsters are solitary animals that prefer to live alone, so it is best to provide each hamster with their own space and resources in their cage.
Six, because the question didn't mention someone taking their body out of the cage.
about eight water bottles
two per cage for dwarf hamsters but for other types one peer cage ask at the pet shop just in case though
If you mean without a room mate, it is more then not cruel. Actually, it would be slightly cruel to put 2 hamsters together, if one or both isn't young. Unless you have a huge cage. If you mean abandoning a hamster, yes. For hamsters had been domesticated to humans for many, many, many generations and aren't used to being back in the wild again. They can't get food or water by themselves, either. Not when they're locked in a cage, THAT'S for sure! Not just for Russian hamsters, all hamsters! Not just for that other answer, but both answers.
About 19 20-ounce bottles.
There are approximately 1.056 16.9 oz bottles of water in a liter.
Most bottles contain 16.9oz of water, so five bottles have around 80oz.