81000885 has 16 divisors (see below), whose sum is σ = 148116096. Its totient is φ = 37028928.

The previous prime is 81000859. The next prime is 81000893. The reversal of 81000885 is 58800018.

It is not a de Polignac number, because 81000885 - 2⁷ = 81000757 is a prime.

It is a super-2 number, since 2×81000885² = 13122286741566450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 385614 + ... + 385823.

It is an arithmetic number, because the mean of its divisors is an integer number (9257256).

Almost surely, 2^81000885 is an apocalyptic number.

It is an amenable number.

81000885 is a deficient number, since it is larger than the sum of its proper divisors (67115211).

81000885 is a wasteful number, since it uses less digits than its factorization.

81000885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 771452.

The product of its (nonzero) digits is 2560, while the sum is 30.

The square root of 81000885 is about 9000.0491665324. The cubic root of 81000885 is about 432.6764468777.

The spelling of 81000885 in words is "eighty-one million, eight hundred eighty-five", and thus it is an aban number.