18043398 has 40 divisors (see below), whose sum is σ = 40795392. Its totient is φ = 5960304.

The previous prime is 18043393. The next prime is 18043469. The reversal of 18043398 is 89334081.

It is a super-2 number, since 2×18043398² = 651128422772808, which contains 22 as substring.

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 19 ways as a sum of consecutive naturals, for example, 20136 + ... + 21012.

Almost surely, 2^18043398 is an apocalyptic number.

18043398 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18043398, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20397696).

18043398 is an abundant number, since it is smaller than the sum of its proper divisors (22751994).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18043398 is a wasteful number, since it uses less digits than its factorization.

18043398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1018 (or 1009 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 18043398 is about 4247.7521114114. The cubic root of 18043398 is about 262.2845906288.

The spelling of 18043398 in words is "eighteen million, forty-three thousand, three hundred ninety-eight".