18181028 has 12 divisors (see below), whose sum is σ = 32914140. Its totient is φ = 8776992.

The previous prime is 18181021. The next prime is 18181039. The reversal of 18181028 is 82018181.

It can be written as a sum of positive squares in 2 ways, for example, as 8988004 + 9193024 = 2998^2 + 3032^2 .

It is a Harshad number since it is a multiple of its sum of digits (29).

It is not an unprimeable number, because it can be changed into a prime (18181021) 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, 78251 + ... + 78482.

It is an arithmetic number, because the mean of its divisors is an integer number (2742845).

Almost surely, 2^18181028 is an apocalyptic number.

It is an amenable number.

18181028 is a deficient number, since it is larger than the sum of its proper divisors (14733112).

18181028 is a wasteful number, since it uses less digits than its factorization.

18181028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156766 (or 156764 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 29.

The square root of 18181028 is about 4263.9216690741. The cubic root of 18181028 is about 262.9497800567.

The spelling of 18181028 in words is "eighteen million, one hundred eighty-one thousand, twenty-eight".