18000015 has 48 divisors (see below), whose sum is σ = 32711040. Its totient is φ = 8379840.

The previous prime is 17999987. The next prime is 18000041. The reversal of 18000015 is 51000081.

It is a happy number.

It is not a de Polignac number, because 18000015 - 2⁹ = 17999503 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a junction number, because it is equal to n+sod(n) for n = 17999958 and 18000003.

It is a congruent number.

It is an unprimeable number.

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 in 47 ways as a sum of consecutive naturals, for example, 305056 + ... + 305114.

It is an arithmetic number, because the mean of its divisors is an integer number (681480).

Almost surely, 2^18000015 is an apocalyptic number.

18000015 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18000015 is a deficient number, since it is larger than the sum of its proper divisors (14711025).

18000015 is a wasteful number, since it uses less digits than its factorization.

18000015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164 (or 121 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 18000015 is about 4242.6424548859. The cubic root of 18000015 is about 262.0742122192.

Adding to 18000015 its reverse (51000081), we get a palindrome (69000096).

The spelling of 18000015 in words is "eighteen million, fifteen", and thus it is an aban number and an uban number.