18905317 has 2 divisors, whose sum is σ = 18905318. Its totient is φ = 18905316.

The previous prime is 18905279. The next prime is 18905329. The reversal of 18905317 is 71350981.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18395521 + 509796 = 4289^2 + 714^2 .

It is a cyclic number.

It is not a de Polignac number, because 18905317 - 2¹⁵ = 18872549 is a prime.

It is a super-2 number, since 2×18905317² = 714822021740978, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18905357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9452658 + 9452659.

It is an arithmetic number, because the mean of its divisors is an integer number (9452659).

Almost surely, 2^18905317 is an apocalyptic number.

It is an amenable number.

18905317 is a deficient number, since it is larger than the sum of its proper divisors (1).

18905317 is an equidigital number, since it uses as much as digits as its factorization.

18905317 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 34.

The square root of 18905317 is about 4348.0244939512. The cubic root of 18905317 is about 266.3961769404.

The spelling of 18905317 in words is "eighteen million, nine hundred five thousand, three hundred seventeen".