81650592 has 180 divisors, whose sum is σ = 257428710. Its totient is φ = 25380864.

The previous prime is 81650587. The next prime is 81650617. The reversal of 81650592 is 29505618.

It is a happy number.

81650592 is a `hidden beast` number, since 8 + 1 + 65 + 0 + 592 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 81649296 + 1296 = 9036^2 + 36^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 749034 + ... + 749142.

Almost surely, 2^81650592 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 81650592, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128714355).

81650592 is an abundant number, since it is smaller than the sum of its proper divisors (175778118).

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

81650592 is a wasteful number, since it uses less digits than its factorization.

81650592 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 81650592 is about 9036.0717128628. The cubic root of 81650592 is about 433.8301982501.

The spelling of 81650592 in words is "eighty-one million, six hundred fifty thousand, five hundred ninety-two".