18508417 has 2 divisors, whose sum is σ = 18508418. Its totient is φ = 18508416.

The previous prime is 18508411. The next prime is 18508439. The reversal of 18508417 is 71480581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18395521 + 112896 = 4289^2 + 336^2 .

It is an emirp because it is prime and its reverse (71480581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18508417 - 2¹⁵ = 18475649 is a prime.

It is a super-2 number, since 2×18508417² = 685122999691778, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18508411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9254208 + 9254209.

It is an arithmetic number, because the mean of its divisors is an integer number (9254209).

Almost surely, 2^18508417 is an apocalyptic number.

It is an amenable number.

18508417 is a deficient number, since it is larger than the sum of its proper divisors (1).

18508417 is an equidigital number, since it uses as much as digits as its factorization.

18508417 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8960, while the sum is 34.

The square root of 18508417 is about 4302.1409786291. The cubic root of 18508417 is about 264.5187277618.

Adding to 18508417 its reverse (71480581), we get a palindrome (89988998).

The spelling of 18508417 in words is "eighteen million, five hundred eight thousand, four hundred seventeen".