18240404 has 24 divisors (see below), whose sum is σ = 39287808. Its totient is φ = 7215840.

The previous prime is 18240401. The next prime is 18240407. The reversal of 18240404 is 40404281.

It is an interprime number because it is at equal distance from previous prime (18240401) and next prime (18240407).

It is a Smith number, since the sum of its digits (23) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 18240404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18240401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24692 + ... + 25419.

It is an arithmetic number, because the mean of its divisors is an integer number (1636992).

Almost surely, 2^18240404 is an apocalyptic number.

18240404 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

18240404 is an abundant number, since it is smaller than the sum of its proper divisors (21047404).

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

18240404 is a wasteful number, since it uses less digits than its factorization.

18240404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50135 (or 50133 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 23.

The square root of 18240404 is about 4270.8785981341. The cubic root of 18240404 is about 263.2357180610.

Adding to 18240404 its reverse (40404281), we get a palindrome (58644685).

The spelling of 18240404 in words is "eighteen million, two hundred forty thousand, four hundred four".