18664539 has 16 divisors (see below), whose sum is σ = 25727520. Its totient is φ = 12026880.

The previous prime is 18664501. The next prime is 18664543. The reversal of 18664539 is 93546681.

It is not a de Polignac number, because 18664539 - 2⁷ = 18664411 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18664539.

It is not an unprimeable number, because it can be changed into a prime (18664579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19627 + ... + 20555.

It is an arithmetic number, because the mean of its divisors is an integer number (1607970).

Almost surely, 2^18664539 is an apocalyptic number.

18664539 is a deficient number, since it is larger than the sum of its proper divisors (7062981).

18664539 is a wasteful number, since it uses less digits than its factorization.

18664539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1150.

The product of its digits is 155520, while the sum is 42.

The square root of 18664539 is about 4320.2475623510. The cubic root of 18664539 is about 265.2604014442.

The spelling of 18664539 in words is "eighteen million, six hundred sixty-four thousand, five hundred thirty-nine".