81590512 has 40 divisors (see below), whose sum is σ = 164052992. Its totient is φ = 39268800.

The previous prime is 81590501. The next prime is 81590521. The reversal of 81590512 is 21509518.

It is a Harshad number since it is a multiple of its sum of digits (31).

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, 134113 + ... + 134719.

Almost surely, 2^81590512 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 81590512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82026496).

81590512 is an abundant number, since it is smaller than the sum of its proper divisors (82462480).

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

81590512 is a wasteful number, since it uses less digits than its factorization.

81590512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 917 (or 911 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 31.

The square root of 81590512 is about 9032.7466476150. The cubic root of 81590512 is about 433.7237654074.

The spelling of 81590512 in words is "eighty-one million, five hundred ninety thousand, five hundred twelve".