18356401440 has 1080 divisors, whose sum is σ = 77088197340. Its totient is φ = 4106059776.

The previous prime is 18356401421. The next prime is 18356401493. The reversal of 18356401440 is 4410465381.

18356401440 is a `hidden beast` number, since 1 + 8 + 3 + 5 + 640 + 1 + 4 + 4 + 0 = 666.

It can be written as a sum of positive squares in 18 ways, for example, as 431475984 + 17924925456 = 20772^2 + 133884^2 .

It is a tau number, because it is divible by the number of its divisors (1080).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 18356401395 and 18356401404.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 179 ways as a sum of consecutive naturals, for example, 632979346 + ... + 632979374.

Almost surely, 2^18356401440 is an apocalyptic number.

18356401440 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 18356401440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38544098670).

18356401440 is an abundant number, since it is smaller than the sum of its proper divisors (58731795900).

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

18356401440 is a wasteful number, since it uses less digits than its factorization.

18356401440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116 (or 69 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The spelling of 18356401440 in words is "eighteen billion, three hundred fifty-six million, four hundred one thousand, four hundred forty".