18040728 has 32 divisors (see below), whose sum is σ = 47476800. Its totient is φ = 5696928.

The previous prime is 18040703. The next prime is 18040751. The reversal of 18040728 is 82704081.

It is a junction number, because it is equal to n+sod(n) for n = 18040695 and 18040704.

It is a congruent number.

It is an unprimeable number.

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, 19326 + ... + 20237.

It is an arithmetic number, because the mean of its divisors is an integer number (1483650).

Almost surely, 2^18040728 is an apocalyptic number.

It is an amenable number.

18040728 is an abundant number, since it is smaller than the sum of its proper divisors (29436072).

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

18040728 is a wasteful number, since it uses less digits than its factorization.

18040728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39591 (or 39587 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 18040728 is about 4247.4378159074. The cubic root of 18040728 is about 262.2716526667.

The spelling of 18040728 in words is "eighteen million, forty thousand, seven hundred twenty-eight".