18308393 has 2 divisors, whose sum is σ = 18308394. Its totient is φ = 18308392.

The previous prime is 18308387. The next prime is 18308399. The reversal of 18308393 is 39380381.

It is a balanced prime because it is at equal distance from previous prime (18308387) and next prime (18308399).

It can be written as a sum of positive squares in only one way, i.e., 13344409 + 4963984 = 3653^2 + 2228^2 .

It is a cyclic number.

It is not a de Polignac number, because 18308393 - 2⁸ = 18308137 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18308399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9154196 + 9154197.

It is an arithmetic number, because the mean of its divisors is an integer number (9154197).

Almost surely, 2^18308393 is an apocalyptic number.

It is an amenable number.

18308393 is a deficient number, since it is larger than the sum of its proper divisors (1).

18308393 is an equidigital number, since it uses as much as digits as its factorization.

18308393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 18308393 is about 4278.8307982438. The cubic root of 18308393 is about 263.5623727899.

The spelling of 18308393 in words is "eighteen million, three hundred eight thousand, three hundred ninety-three".