18728978440032 has 72 divisors (see below), whose sum is σ = 60869179936656. Its totient is φ = 5351136696576.

The previous prime is 18728978440027. The next prime is 18728978440141. The reversal of 18728978440032 is 23004487982781.

18728978440032 is a `hidden beast` number, since 1 + 8 + 72 + 8 + 97 + 8 + 440 + 0 + 32 = 666.

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

It is a super-2 number, since 2×18728978440032² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4645081923 + ... + 4645085954.

It is an arithmetic number, because the mean of its divisors is an integer number (845405276898).

Almost surely, 2^{18728978440032} is an apocalyptic number.

18728978440032 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

18728978440032 is an abundant number, since it is smaller than the sum of its proper divisors (42140201496624).

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

18728978440032 is a wasteful number, since it uses less digits than its factorization.

18728978440032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9290167900 (or 9290167889 counting only the distinct ones).

The product of its (nonzero) digits is 43352064, while the sum is 63.

The spelling of 18728978440032 in words is "eighteen trillion, seven hundred twenty-eight billion, nine hundred seventy-eight million, four hundred forty thousand, thirty-two".