18164643840 has 576 divisors, whose sum is σ = 73990687680. Its totient is φ = 4034396160.

The previous prime is 18164643799. The next prime is 18164643851. The reversal of 18164643840 is 4834646181.

18164643840 is a `hidden beast` number, since 18 + 164 + 6 + 438 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 23869060 + ... + 23869820.

It is an arithmetic number, because the mean of its divisors is an integer number (128456055).

Almost surely, 2^18164643840 is an apocalyptic number.

18164643840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18164643840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36995343840).

18164643840 is an abundant number, since it is smaller than the sum of its proper divisors (55826043840).

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

18164643840 is a wasteful number, since it uses less digits than its factorization.

18164643840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 838 (or 815 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The spelling of 18164643840 in words is "eighteen billion, one hundred sixty-four million, six hundred forty-three thousand, eight hundred forty".