81858112 has 56 divisors (see below), whose sum is σ = 188260736. Its totient is φ = 34587648.

The previous prime is 81858109. The next prime is 81858131. The reversal of 81858112 is 21185818.

It is a tau number, because it is divible by the number of its divisors (56).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31453 + ... + 33955.

Almost surely, 2^81858112 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81858112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94130368).

81858112 is an abundant number, since it is smaller than the sum of its proper divisors (106402624).

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

81858112 is a wasteful number, since it uses less digits than its factorization.

81858112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2595 (or 2585 counting only the distinct ones).

The product of its digits is 5120, while the sum is 34.

The square root of 81858112 is about 9047.5472919460. The cubic root of 81858112 is about 434.1974226923.

The spelling of 81858112 in words is "eighty-one million, eight hundred fifty-eight thousand, one hundred twelve".