18039564 has 24 divisors (see below), whose sum is σ = 46769520. Its totient is φ = 6013152.

The previous prime is 18039563. The next prime is 18039577. The reversal of 18039564 is 46593081.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (18039563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 83409 + ... + 83624.

It is an arithmetic number, because the mean of its divisors is an integer number (1948730).

Almost surely, 2^18039564 is an apocalyptic number.

It is an amenable number.

18039564 is an abundant number, since it is smaller than the sum of its proper divisors (28729956).

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

18039564 is a wasteful number, since it uses less digits than its factorization.

18039564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167046 (or 167038 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 18039564 is about 4247.3007899135. The cubic root of 18039564 is about 262.2660118971.

The spelling of 18039564 in words is "eighteen million, thirty-nine thousand, five hundred sixty-four".