18031338 has 48 divisors (see below), whose sum is σ = 42378336. Its totient is φ = 5508000.

The previous prime is 18031309. The next prime is 18031357. The reversal of 18031338 is 83313081.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

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 23 ways as a sum of consecutive naturals, for example, 58581 + ... + 58887.

It is an arithmetic number, because the mean of its divisors is an integer number (882882).

Almost surely, 2^18031338 is an apocalyptic number.

18031338 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 18031338, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21189168).

18031338 is an abundant number, since it is smaller than the sum of its proper divisors (24346998).

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

18031338 is a wasteful number, since it uses less digits than its factorization.

18031338 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579 (or 576 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 18031338 is about 4246.3322997618. The cubic root of 18031338 is about 262.2261416020.

The spelling of 18031338 in words is "eighteen million, thirty-one thousand, three hundred thirty-eight".