18073638 has 32 divisors (see below), whose sum is σ = 43816320. Its totient is φ = 5476680.

The previous prime is 18073637. The next prime is 18073687. The reversal of 18073638 is 83637081.

18073638 is a `hidden beast` number, since 18 + 0 + 7 + 3 + 638 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18073637) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14620 + ... + 15807.

It is an arithmetic number, because the mean of its divisors is an integer number (1369260).

Almost surely, 2^18073638 is an apocalyptic number.

18073638 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18073638 is an abundant number, since it is smaller than the sum of its proper divisors (25742682).

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

18073638 is a wasteful number, since it uses less digits than its factorization.

18073638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30449 (or 30443 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 18073638 is about 4251.3101510005. The cubic root of 18073638 is about 262.4310349440.

It can be divided in two parts, 1807 and 3638, that added together give a palindrome (5445).

The spelling of 18073638 in words is "eighteen million, seventy-three thousand, six hundred thirty-eight".