18000138 has 16 divisors (see below), whose sum is σ = 38769696. Its totient is φ = 5538480.

The previous prime is 18000137. The next prime is 18000139. The reversal of 18000138 is 83100081.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (18000137) and next prime (18000139).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18000137) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115308 + ... + 115463.

It is an arithmetic number, because the mean of its divisors is an integer number (2423106).

Almost surely, 2^18000138 is an apocalyptic number.

18000138 is an abundant number, since it is smaller than the sum of its proper divisors (20769558).

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

18000138 is a wasteful number, since it uses less digits than its factorization.

18000138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230789.

The product of its (nonzero) digits is 192, while the sum is 21.

The square root of 18000138 is about 4242.6569505441. The cubic root of 18000138 is about 262.0748091642.

The spelling of 18000138 in words is "eighteen million, one hundred thirty-eight", and thus it is an aban number.