18243999 has 6 divisors (see below), whose sum is σ = 26352456. Its totient is φ = 12162660.

The previous prime is 18243989. The next prime is 18244001. The reversal of 18243999 is 99934281.

It is not a de Polignac number, because 18243999 - 2⁴ = 18243983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18243949) 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 in 5 ways as a sum of consecutive naturals, for example, 1013547 + ... + 1013564.

It is an arithmetic number, because the mean of its divisors is an integer number (4392076).

Almost surely, 2^18243999 is an apocalyptic number.

18243999 is a deficient number, since it is larger than the sum of its proper divisors (8108457).

18243999 is a wasteful number, since it uses less digits than its factorization.

18243999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2027117 (or 2027114 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 18243999 is about 4271.2994509868. The cubic root of 18243999 is about 263.2530106284.

The spelling of 18243999 in words is "eighteen million, two hundred forty-three thousand, nine hundred ninety-nine".