81806592 has 72 divisors (see below), whose sum is σ = 248844736. Its totient is φ = 23371776.

The previous prime is 81806579. The next prime is 81806611. The reversal of 81806592 is 29560818.

It is a self number, because there is not a number n which added to its sum of digits gives 81806592.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2233 + ... + 12984.

Almost surely, 2^81806592 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 81806592, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124422368).

81806592 is an abundant number, since it is smaller than the sum of its proper divisors (167038144).

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

81806592 is a wasteful number, since it uses less digits than its factorization.

81806592 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15243 (or 15229 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 39.

The square root of 81806592 is about 9044.6996633387. The cubic root of 81806592 is about 434.1063116004.

The spelling of 81806592 in words is "eighty-one million, eight hundred six thousand, five hundred ninety-two".