18378009 has 40 divisors (see below), whose sum is σ = 30573312. Its totient is φ = 10925280.

The previous prime is 18377993. The next prime is 18378013. The reversal of 18378009 is 90087381.

It is not a de Polignac number, because 18378009 - 2⁴ = 18377993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18378029) by changing a digit.

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 39 ways as a sum of consecutive naturals, for example, 32362 + ... + 32924.

Almost surely, 2^18378009 is an apocalyptic number.

It is an amenable number.

18378009 is a deficient number, since it is larger than the sum of its proper divisors (12195303).

18378009 is a wasteful number, since it uses less digits than its factorization.

18378009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 619 (or 610 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 18378009 is about 4286.9580123906. The cubic root of 18378009 is about 263.8960075954.

The spelling of 18378009 in words is "eighteen million, three hundred seventy-eight thousand, nine".