18031400 has 48 divisors (see below), whose sum is σ = 42435900. Its totient is φ = 7124480.

The previous prime is 18031381. The next prime is 18031421. The reversal of 18031400 is 413081.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 206116 + 17825284 = 454^2 + 4222^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17294 + ... + 18306.

Almost surely, 2^18031400 is an apocalyptic number.

18031400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18031400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21217950).

18031400 is an abundant number, since it is smaller than the sum of its proper divisors (24404500).

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

18031400 is a wasteful number, since it uses less digits than its factorization.

18031400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1118 (or 1109 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 18031400 is about 4246.3396001733. The cubic root of 18031400 is about 262.2264421528.

Adding to 18031400 its reverse (413081), we get a palindrome (18444481).

The spelling of 18031400 in words is "eighteen million, thirty-one thousand, four hundred".