18215535840 has 192 divisors, whose sum is σ = 58136279040. Its totient is φ = 4793702400.

The previous prime is 18215535839. The next prime is 18215535869. The reversal of 18215535840 is 4853551281.

It is a junction number, because it is equal to n+sod(n) for n = 18215535792 and 18215535801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 29427051 + ... + 29427669.

It is an arithmetic number, because the mean of its divisors is an integer number (302793120).

Almost surely, 2^18215535840 is an apocalyptic number.

18215535840 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 18215535840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29068139520).

18215535840 is an abundant number, since it is smaller than the sum of its proper divisors (39920743200).

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

18215535840 is a wasteful number, since it uses less digits than its factorization.

18215535840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1345 (or 1337 counting only the distinct ones).

The product of its (nonzero) digits is 192000, while the sum is 42.

The spelling of 18215535840 in words is "eighteen billion, two hundred fifteen million, five hundred thirty-five thousand, eight hundred forty".