18315999 has 24 divisors (see below), whose sum is σ = 29268512. Its totient is φ = 10964160.

The previous prime is 18315989. The next prime is 18316003. The reversal of 18315999 is 99951381.

It is not a de Polignac number, because 18315999 - 2⁸ = 18315743 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18315929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2214 + ... + 6444.

Almost surely, 2^18315999 is an apocalyptic number.

18315999 is a deficient number, since it is larger than the sum of its proper divisors (10952513).

18315999 is a wasteful number, since it uses less digits than its factorization.

18315999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4287 (or 4284 counting only the distinct ones).

The product of its digits is 87480, while the sum is 45.

The square root of 18315999 is about 4279.7195001542. The cubic root of 18315999 is about 263.5988656681.

The spelling of 18315999 in words is "eighteen million, three hundred fifteen thousand, nine hundred ninety-nine".