18381028 has 12 divisors (see below), whose sum is σ = 32252220. Its totient is φ = 9166112.

The previous prime is 18381023. The next prime is 18381031. The reversal of 18381028 is 82018381.

It can be written as a sum of positive squares in 2 ways, for example, as 5721664 + 12659364 = 2392^2 + 3558^2 .

It is not an unprimeable number, because it can be changed into a prime (18381023) 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 3 ways as a sum of consecutive naturals, for example, 4351 + ... + 7462.

It is an arithmetic number, because the mean of its divisors is an integer number (2687685).

Almost surely, 2^18381028 is an apocalyptic number.

It is an amenable number.

18381028 is a deficient number, since it is larger than the sum of its proper divisors (13871192).

18381028 is a wasteful number, since it uses less digits than its factorization.

18381028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12206 (or 12204 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 31.

The square root of 18381028 is about 4287.3101124131. The cubic root of 18381028 is about 263.9104570827.

The spelling of 18381028 in words is "eighteen million, three hundred eighty-one thousand, twenty-eight".