18185489856 has 168 divisors, whose sum is σ = 54500434560. Its totient is φ = 5786694144.

The previous prime is 18185489837. The next prime is 18185489863. The reversal of 18185489856 is 65898458181.

18185489856 is a `hidden beast` number, since 1 + 8 + 1 + 8 + 548 + 9 + 85 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 18185489793 and 18185489802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8729391 + ... + 8731473.

Almost surely, 2^18185489856 is an apocalyptic number.

18185489856 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 18185489856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27250217280).

18185489856 is an abundant number, since it is smaller than the sum of its proper divisors (36314944704).

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

18185489856 is a wasteful number, since it uses less digits than its factorization.

18185489856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2783 (or 2770 counting only the distinct ones).

The product of its digits is 22118400, while the sum is 63.

The spelling of 18185489856 in words is "eighteen billion, one hundred eighty-five million, four hundred eighty-nine thousand, eight hundred fifty-six".