18388705536 has 180 divisors, whose sum is σ = 55240557372. Its totient is φ = 6083887104.

The previous prime is 18388705523. The next prime is 18388705553. The reversal of 18388705536 is 63550788381.

18388705536 is a `hidden beast` number, since 1 + 8 + 3 + 8 + 87 + 0 + 553 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 6879707136 + 11508998400 = 82944^2 + 107280^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2837596 + ... + 2844068.

Almost surely, 2^18388705536 is an apocalyptic number.

18388705536 is a gapful number since it is divisible by the number (16) 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 18388705536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27620278686).

18388705536 is an abundant number, since it is smaller than the sum of its proper divisors (36851851836).

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

18388705536 is an equidigital number, since it uses as much as digits as its factorization.

18388705536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6638 (or 6615 counting only the distinct ones).

The product of its (nonzero) digits is 4838400, while the sum is 54.

The spelling of 18388705536 in words is "eighteen billion, three hundred eighty-eight million, seven hundred five thousand, five hundred thirty-six".