81885800 has 24 divisors (see below), whose sum is σ = 190384950. Its totient is φ = 32754240.

The previous prime is 81885799. The next prime is 81885841. The reversal of 81885800 is 858818.

It can be written as a sum of positive squares in 3 ways, for example, as 49646116 + 32239684 = 7046^2 + 5678^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 204515 + ... + 204914.

Almost surely, 2^81885800 is an apocalyptic number.

It is an amenable number.

81885800 is an abundant number, since it is smaller than the sum of its proper divisors (108499150).

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

81885800 is a wasteful number, since it uses less digits than its factorization.

81885800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409445 (or 409436 counting only the distinct ones).

The product of its (nonzero) digits is 20480, while the sum is 38.

The square root of 81885800 is about 9049.0773010291. The cubic root of 81885800 is about 434.2463720379.

The spelling of 81885800 in words is "eighty-one million, eight hundred eighty-five thousand, eight hundred".