There are approximately 4,600 known species of cockroaches worldwide. However, it's worth noting that the actual number of species could be higher, as new species are constantly being discovered and described by scientists. These insects are incredibly adaptable and can be found in various habitats across the globe, except for polar regions. Among the thousands of species, a few common ones include the German cockroach, American cockroach, Oriental cockroach, and Australian cockroach. Each species has its own unique characteristics, behaviours, and preferred habitats.