181536840 has 48 divisors (see below), whose sum is σ = 589995900. Its totient is φ = 48409728.

The previous prime is 181536821. The next prime is 181536877. The reversal of 181536840 is 48635181.

181536840 is a `hidden beast` number, since 1 + 81 + 536 + 8 + 40 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 165328164 + 16208676 = 12858^2 + 4026^2 .

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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 = 181536795 and 181536804.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 251775 + ... + 252494.

Almost surely, 2^181536840 is an apocalyptic number.

181536840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

181536840 is an abundant number, since it is smaller than the sum of its proper divisors (408459060).

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

181536840 is a wasteful number, since it uses less digits than its factorization.

181536840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504286 (or 504279 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 181536840 is about 13473.5607765728. The cubic root of 181536840 is about 566.2239787466.

The spelling of 181536840 in words is "one hundred eighty-one million, five hundred thirty-six thousand, eight hundred forty".