81009573588 has 72 divisors (see below), whose sum is σ = 212017085280. Its totient is φ = 26049683520.

The previous prime is 81009573583. The next prime is 81009573607. The reversal of 81009573588 is 88537590018.

81009573588 is a `hidden beast` number, since 8 + 1 + 0 + 0 + 9 + 57 + 3 + 588 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81009573583) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1206543 + ... + 1271913.

It is an arithmetic number, because the mean of its divisors is an integer number (2944681740).

Almost surely, 2^81009573588 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 81009573588, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106008542640).

81009573588 is an abundant number, since it is smaller than the sum of its proper divisors (131007511692).

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

81009573588 is a wasteful number, since it uses less digits than its factorization.

81009573588 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66597 (or 66592 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 54.

The spelling of 81009573588 in words is "eighty-one billion, nine million, five hundred seventy-three thousand, five hundred eighty-eight".