18638910318 has 64 divisors (see below), whose sum is σ = 43125050880. Its totient is φ = 5260574592.

The previous prime is 18638910307. The next prime is 18638910319. The reversal of 18638910318 is 81301983681.

It is a super-2 number, since 2×18638910318² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18638910319) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1132593 + ... + 1148931.

It is an arithmetic number, because the mean of its divisors is an integer number (673828920).

Almost surely, 2^18638910318 is an apocalyptic number.

18638910318 is an abundant number, since it is smaller than the sum of its proper divisors (24486140562).

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

18638910318 is a wasteful number, since it uses less digits than its factorization.

18638910318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16681.

The product of its (nonzero) digits is 248832, while the sum is 48.

The spelling of 18638910318 in words is "eighteen billion, six hundred thirty-eight million, nine hundred ten thousand, three hundred eighteen".