Тройка: three of something
If numbers can be said to have personalities, три (three) is deeply conflicted. It is highly spiritual but sometimes very naughty. It is a very small amount of something, unless it is more than you can imagine. It is average and in between, but at the same time it is exalted and magical. If три were a person, he would be on drugs.
Of course, три is just the number three, helpfully defined as more than two and less than four. Три describes three units of something, like три часа ночи (3 a.m.; literally and properly "at night" in Russian).