81856110 has 32 divisors (see below), whose sum is σ = 224520192. Its totient is φ = 18709920.

The previous prime is 81856109. The next prime is 81856147. The reversal of 81856110 is 1165818.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 194686 + ... + 195105.

It is an arithmetic number, because the mean of its divisors is an integer number (7016256).

Almost surely, 2^81856110 is an apocalyptic number.

81856110 is an abundant number, since it is smaller than the sum of its proper divisors (142664082).

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

81856110 is a wasteful number, since it uses less digits than its factorization.

81856110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389808.

The product of its (nonzero) digits is 1920, while the sum is 30.

The square root of 81856110 is about 9047.4366535500. The cubic root of 81856110 is about 434.1938829482.

The spelling of 81856110 in words is "eighty-one million, eight hundred fifty-six thousand, one hundred ten".