18681232 has 40 divisors (see below), whose sum is σ = 38642616. Its totient is φ = 8718336.

The previous prime is 18681227. The next prime is 18681239. The reversal of 18681232 is 23218681.

It can be written as a sum of positive squares in 4 ways, for example, as 10863616 + 7817616 = 3296^2 + 2796^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18681194 and 18681203.

It is not an unprimeable number, because it can be changed into a prime (18681239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46858 + ... + 47254.

Almost surely, 2^18681232 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18681232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19321308).

18681232 is an abundant number, since it is smaller than the sum of its proper divisors (19961384).

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

18681232 is a wasteful number, since it uses less digits than its factorization.

18681232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 595 (or 589 counting only the distinct ones).

The product of its digits is 4608, while the sum is 31.

The square root of 18681232 is about 4322.1790800475. The cubic root of 18681232 is about 265.3394581776.

It can be divided in two parts, 186 and 81232, that added together give a palindrome (81418).

The spelling of 18681232 in words is "eighteen million, six hundred eighty-one thousand, two hundred thirty-two".