|Discovered by||Darling, D. J.|
|Number of||23 known|
|Description||A prime which remains prime even when cycled.|
|First Few||2, 3, 5, 7, 11, 13, 17, 31|
Circular primes are the primes that can remain prime on any cyclic rotation of their digits. Take 197, for example, when "1" is dragged to the right, it becomes 971, which is also a prime number. With the same process, 719 is also a prime number. Therefore, 197, 971, and 719 are all circular primes.