81090912 has 48 divisors (see below), whose sum is σ = 243274752. Its totient is φ = 23168640.

The previous prime is 81090871. The next prime is 81090929. The reversal of 81090912 is 21909018.

It is a tau number, because it is divible by the number of its divisors (48).

It is a self number, because there is not a number n which added to its sum of digits gives 81090912.

It is a congruent number.

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, 59664 + ... + 61007.

It is an arithmetic number, because the mean of its divisors is an integer number (5068224).

Almost surely, 2^81090912 is an apocalyptic number.

It is an amenable number.

81090912 is an abundant number, since it is smaller than the sum of its proper divisors (162183840).

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

81090912 is a wasteful number, since it uses less digits than its factorization.

81090912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120691 (or 120683 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 30.

The square root of 81090912 is about 9005.0492502818. The cubic root of 81090912 is about 432.8366843876.

The spelling of 81090912 in words is "eighty-one million, ninety thousand, nine hundred twelve".