181821856392 has 384 divisors, whose sum is σ = 583431413760. Its totient is φ = 50594818560.

The previous prime is 181821856379. The next prime is 181821856397. The reversal of 181821856392 is 293658128181.

181821856392 is a `hidden beast` number, since 18 + 182 + 18 + 56 + 392 = 666.

181821856392 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (181821856397) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 45374053 + ... + 45378059.

It is an arithmetic number, because the mean of its divisors is an integer number (1519352640).

Almost surely, 2^181821856392 is an apocalyptic number.

181821856392 is a gapful number since it is divisible by the number (12) 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 181821856392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (291715706880).

181821856392 is an abundant number, since it is smaller than the sum of its proper divisors (401609557368).

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

181821856392 is a wasteful number, since it uses less digits than its factorization.

181821856392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4153 (or 4146 counting only the distinct ones).

The product of its digits is 1658880, while the sum is 54.

The spelling of 181821856392 in words is "one hundred eighty-one billion, eight hundred twenty-one million, eight hundred fifty-six thousand, three hundred ninety-two".