18306438 has 16 divisors (see below), whose sum is σ = 36860400. Its totient is φ = 6060896.

The previous prime is 18306419. The next prime is 18306451. The reversal of 18306438 is 83460381.

It is a junction number, because it is equal to n+sod(n) for n = 18306399 and 18306408.

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, 9345 + ... + 11132.

It is an arithmetic number, because the mean of its divisors is an integer number (2303775).

Almost surely, 2^18306438 is an apocalyptic number.

18306438 is an abundant number, since it is smaller than the sum of its proper divisors (18553962).

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

18306438 is a wasteful number, since it uses less digits than its factorization.

18306438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20631.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 18306438 is about 4278.6023418869. The cubic root of 18306438 is about 263.5529912496.

The spelling of 18306438 in words is "eighteen million, three hundred six thousand, four hundred thirty-eight".