18378438 has 16 divisors (see below), whose sum is σ = 39584496. Its totient is φ = 5654880.

The previous prime is 18378401. The next prime is 18378461. The reversal of 18378438 is 83487381.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18378438.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117733 + ... + 117888.

It is an arithmetic number, because the mean of its divisors is an integer number (2474031).

Almost surely, 2^18378438 is an apocalyptic number.

18378438 is an abundant number, since it is smaller than the sum of its proper divisors (21206058).

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

18378438 is a wasteful number, since it uses less digits than its factorization.

18378438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235639.

The product of its digits is 129024, while the sum is 42.

The square root of 18378438 is about 4287.0080475782. The cubic root of 18378438 is about 263.8980609645.

The spelling of 18378438 in words is "eighteen million, three hundred seventy-eight thousand, four hundred thirty-eight".