18042399 has 16 divisors (see below), whose sum is σ = 26864640. Its totient is φ = 11967480.

The previous prime is 18042361. The next prime is 18042463. The reversal of 18042399 is 99324081.

It is not a de Polignac number, because 18042399 - 2¹⁵ = 18009631 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18042319) 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 15 ways as a sum of consecutive naturals, for example, 4114 + ... + 7280.

It is an arithmetic number, because the mean of its divisors is an integer number (1679040).

Almost surely, 2^18042399 is an apocalyptic number.

18042399 is a deficient number, since it is larger than the sum of its proper divisors (8822241).

18042399 is a wasteful number, since it uses less digits than its factorization.

18042399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3387 (or 3381 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 18042399 is about 4247.6345181760. The cubic root of 18042399 is about 262.2797499452.

The spelling of 18042399 in words is "eighteen million, forty-two thousand, three hundred ninety-nine".