18312013440 has 864 divisors, whose sum is σ = 77241024900. Its totient is φ = 4138573824.

The previous prime is 18312013399. The next prime is 18312013459. The reversal of 18312013440 is 4431021381.

18312013440 is a `hidden beast` number, since 1 + 8 + 312 + 0 + 1 + 344 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 17303823936 + 1008189504 = 131544^2 + 31752^2 .

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 205752916 + ... + 205753004.

Almost surely, 2^18312013440 is an apocalyptic number.

18312013440 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 18312013440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38620512450).

18312013440 is an abundant number, since it is smaller than the sum of its proper divisors (58929011460).

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

18312013440 is an frugal number, since it uses more digits than its factorization.

18312013440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146 (or 106 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The spelling of 18312013440 in words is "eighteen billion, three hundred twelve million, thirteen thousand, four hundred forty".