18115938 has 12 divisors (see below), whose sum is σ = 39251238. Its totient is φ = 6038640.

The previous prime is 18115919. The next prime is 18115939. The reversal of 18115938 is 83951181.

It can be written as a sum of positive squares in only one way, i.e., 16136289 + 1979649 = 4017^2 + 1407^2 .

It is not an unprimeable number, because it can be changed into a prime (18115939) 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 5 ways as a sum of consecutive naturals, for example, 503203 + ... + 503238.

Almost surely, 2^18115938 is an apocalyptic number.

18115938 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18115938 is an abundant number, since it is smaller than the sum of its proper divisors (21135300).

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

18115938 is a wasteful number, since it uses less digits than its factorization.

18115938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1006449 (or 1006446 counting only the distinct ones).

The product of its digits is 8640, while the sum is 36.

The square root of 18115938 is about 4256.2821804951. The cubic root of 18115938 is about 262.6356088433.

The spelling of 18115938 in words is "eighteen million, one hundred fifteen thousand, nine hundred thirty-eight".