18043399 has 6 divisors (see below), whose sum is σ = 19832960. Its totient is φ = 16402980.

The previous prime is 18043393. The next prime is 18043469. The reversal of 18043399 is 99334081.

It is not a de Polignac number, because 18043399 - 2³ = 18043391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18043391) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 74439 + ... + 74680.

Almost surely, 2^18043399 is an apocalyptic number.

18043399 is a deficient number, since it is larger than the sum of its proper divisors (1789561).

18043399 is a wasteful number, since it uses less digits than its factorization.

18043399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149141 (or 149130 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 18043399 is about 4247.7522291207. The cubic root of 18043399 is about 262.2845954743.

The spelling of 18043399 in words is "eighteen million, forty-three thousand, three hundred ninety-nine".