18564865020 has 144 divisors (see below), whose sum is σ = 61082592480. Its totient is φ = 4536857088.

The previous prime is 18564865019. The next prime is 18564865061. The reversal of 18564865020 is 2056846581.

18564865020 is a `hidden beast` number, since 1 + 8 + 5 + 64 + 86 + 502 + 0 = 666.

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 (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 296722 + ... + 353798.

It is an arithmetic number, because the mean of its divisors is an integer number (424184670).

Almost surely, 2^18564865020 is an apocalyptic number.

18564865020 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 18564865020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30541296240).

18564865020 is an abundant number, since it is smaller than the sum of its proper divisors (42517727460).

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

18564865020 is a wasteful number, since it uses less digits than its factorization.

18564865020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57244 (or 57239 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 45.

The spelling of 18564865020 in words is "eighteen billion, five hundred sixty-four million, eight hundred sixty-five thousand, twenty".