18216864 has 72 divisors (see below), whose sum is σ = 53044992. Its totient is φ = 5927040.

The previous prime is 18216859. The next prime is 18216881. The reversal of 18216864 is 46861281.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 11649 + ... + 13119.

It is an arithmetic number, because the mean of its divisors is an integer number (736736).

Almost surely, 2^18216864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18216864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26522496).

18216864 is an abundant number, since it is smaller than the sum of its proper divisors (34828128).

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

18216864 is a wasteful number, since it uses less digits than its factorization.

18216864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1530 (or 1519 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 18216864 is about 4268.1218351870. The cubic root of 18216864 is about 263.1224304321.

The spelling of 18216864 in words is "eighteen million, two hundred sixteen thousand, eight hundred sixty-four".