18008917 has 2 divisors, whose sum is σ = 18008918. Its totient is φ = 18008916.

The previous prime is 18008911. The next prime is 18008989. The reversal of 18008917 is 71980081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12292036 + 5716881 = 3506^2 + 2391^2 .

It is an emirp because it is prime and its reverse (71980081) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18008917 - 2¹⁵ = 17976149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18008911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9004458 + 9004459.

It is an arithmetic number, because the mean of its divisors is an integer number (9004459).

Almost surely, 2^18008917 is an apocalyptic number.

It is an amenable number.

18008917 is a deficient number, since it is larger than the sum of its proper divisors (1).

18008917 is an equidigital number, since it uses as much as digits as its factorization.

18008917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 34.

The square root of 18008917 is about 4243.6914355311. The cubic root of 18008917 is about 262.1174084823.

Adding to 18008917 its reverse (71980081), we get a palindrome (89988998).

The spelling of 18008917 in words is "eighteen million, eight thousand, nine hundred seventeen".