181331856 has 30 divisors (see below), whose sum is σ = 507477750. Its totient is φ = 60443904.

The previous prime is 181331827. The next prime is 181331863. The reversal of 181331856 is 658133181.

It can be written as a sum of positive squares in only one way, i.e., 125081856 + 56250000 = 11184^2 + 7500^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 181331856.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 629481 + ... + 629768.

It is an arithmetic number, because the mean of its divisors is an integer number (16915925).

Almost surely, 2^181331856 is an apocalyptic number.

181331856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

181331856 is an abundant number, since it is smaller than the sum of its proper divisors (326145894).

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

181331856 is a wasteful number, since it uses less digits than its factorization.

181331856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1259263 (or 1259254 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 181331856 is about 13465.9517301972. The cubic root of 181331856 is about 566.0107794690.

The spelling of 181331856 in words is "one hundred eighty-one million, three hundred thirty-one thousand, eight hundred fifty-six".