18378940 has 12 divisors (see below), whose sum is σ = 38595816. Its totient is φ = 7351568.

The previous prime is 18378937. The next prime is 18378959. The reversal of 18378940 is 4987381.

It is a junction number, because it is equal to n+sod(n) for n = 18378893 and 18378902.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 459454 + ... + 459493.

It is an arithmetic number, because the mean of its divisors is an integer number (3216318).

Almost surely, 2^18378940 is an apocalyptic number.

18378940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18378940 is an abundant number, since it is smaller than the sum of its proper divisors (20216876).

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

18378940 is a wasteful number, since it uses less digits than its factorization.

18378940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918956 (or 918954 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 18378940 is about 4287.0665961704. The cubic root of 18378940 is about 263.9004637008.

The spelling of 18378940 in words is "eighteen million, three hundred seventy-eight thousand, nine hundred forty".