81069912 has 144 divisors (see below), whose sum is σ = 278764200. Its totient is φ = 21047040.

The previous prime is 81069907. The next prime is 81069959. The reversal of 81069912 is 21996018.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 37764 + ... + 39852.

Almost surely, 2^81069912 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 81069912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139382100).

81069912 is an abundant number, since it is smaller than the sum of its proper divisors (197694288).

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

81069912 is a wasteful number, since it uses less digits than its factorization.

81069912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2126 (or 2112 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 81069912 is about 9003.8831622806. The cubic root of 81069912 is about 432.7993174583.

The spelling of 81069912 in words is "eighty-one million, sixty-nine thousand, nine hundred twelve".