18431000 has 64 divisors (see below), whose sum is σ = 49308480. Its totient is φ = 6316800.

The previous prime is 18430943. The next prime is 18431011. The reversal of 18431000 is 13481.

It is a happy number.

It is a super-2 number, since 2×18431000² = 679403522000000, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18431000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5684 + ... + 8316.

It is an arithmetic number, because the mean of its divisors is an integer number (770445).

Almost surely, 2^18431000 is an apocalyptic number.

18431000 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 18431000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24654240).

18431000 is an abundant number, since it is smaller than the sum of its proper divisors (30877480).

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

18431000 is a wasteful number, since it uses less digits than its factorization.

18431000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2661 (or 2647 counting only the distinct ones).

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

The square root of 18431000 is about 4293.1340533461. The cubic root of 18431000 is about 264.1494027314.

Adding to 18431000 its reverse (13481), we get a palindrome (18444481).

The spelling of 18431000 in words is "eighteen million, four hundred thirty-one thousand".