181839840 has 384 divisors, whose sum is σ = 739694592. Its totient is φ = 36495360.

The previous prime is 181839821. The next prime is 181839857. The reversal of 181839840 is 48938181.

It is a super-2 number, since 2×181839840² = 66131454822451200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 181839792 and 181839801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1004550 + ... + 1004730.

It is an arithmetic number, because the mean of its divisors is an integer number (1926288).

Almost surely, 2^181839840 is an apocalyptic number.

181839840 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 181839840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (369847296).

181839840 is an abundant number, since it is smaller than the sum of its proper divisors (557854752).

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

181839840 is a wasteful number, since it uses less digits than its factorization.

181839840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242 (or 234 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 42.

The square root of 181839840 is about 13484.8003322259. The cubic root of 181839840 is about 566.5388285249.

The spelling of 181839840 in words is "one hundred eighty-one million, eight hundred thirty-nine thousand, eight hundred forty".