18238240 has 24 divisors (see below), whose sum is σ = 43088220. Its totient is φ = 7295232.

The previous prime is 18238223. The next prime is 18238243. The reversal of 18238240 is 4283281.

It can be written as a sum of positive squares in 2 ways, for example, as 17539344 + 698896 = 4188^2 + 836^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18238199 and 18238208.

It is not an unprimeable number, because it can be changed into a prime (18238243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56835 + ... + 57154.

Almost surely, 2^18238240 is an apocalyptic number.

18238240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18238240 is an abundant number, since it is smaller than the sum of its proper divisors (24849980).

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

18238240 is a wasteful number, since it uses less digits than its factorization.

18238240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114004 (or 113996 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 18238240 is about 4270.6252469633. The cubic root of 18238240 is about 263.2253077539.

The spelling of 18238240 in words is "eighteen million, two hundred thirty-eight thousand, two hundred forty".