18231500 has 48 divisors (see below), whose sum is σ = 45514560. Its totient is φ = 6249600.

The previous prime is 18231481. The next prime is 18231509. The reversal of 18231500 is 513281.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (18231509) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 896 + ... + 6104.

It is an arithmetic number, because the mean of its divisors is an integer number (948220).

Almost surely, 2^18231500 is an apocalyptic number.

18231500 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 18231500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22757280).

18231500 is an abundant number, since it is smaller than the sum of its proper divisors (27283060).

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

18231500 is a wasteful number, since it uses less digits than its factorization.

18231500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5235 (or 5223 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 18231500 is about 4269.8360624268. The cubic root of 18231500 is about 263.1928785070.

Adding to 18231500 its reverse (513281), we get a palindrome (18744781).

The spelling of 18231500 in words is "eighteen million, two hundred thirty-one thousand, five hundred".