18664560 has 80 divisors (see below), whose sum is σ = 64296480. Its totient is φ = 4976640.

The previous prime is 18664543. The next prime is 18664561. The reversal of 18664560 is 6546681.

18664560 is a `hidden beast` number, since 1 + 8 + 6 + 645 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18664561) 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 15 ways as a sum of consecutive naturals, for example, 2161 + ... + 6480.

It is an arithmetic number, because the mean of its divisors is an integer number (803706).

Almost surely, 2^18664560 is an apocalyptic number.

18664560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18664560 is an abundant number, since it is smaller than the sum of its proper divisors (45631920).

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

18664560 is a wasteful number, since it uses less digits than its factorization.

18664560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8663 (or 8651 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 18664560 is about 4320.2499927666. The cubic root of 18664560 is about 265.2605009282.

It can be divided in two parts, 186 and 64560, that added together give a palindrome (64746).

The spelling of 18664560 in words is "eighteen million, six hundred sixty-four thousand, five hundred sixty".