81673592 has 192 divisors, whose sum is σ = 220631040. Its totient is φ = 27820800.

The previous prime is 81673589. The next prime is 81673637. The reversal of 81673592 is 29537618.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1737713 + ... + 1737759.

It is an arithmetic number, because the mean of its divisors is an integer number (1149120).

Almost surely, 2^81673592 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 81673592, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110315520).

81673592 is an abundant number, since it is smaller than the sum of its proper divisors (138957448).

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

81673592 is a wasteful number, since it uses less digits than its factorization.

81673592 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 111 counting only the distinct ones).

The product of its digits is 90720, while the sum is 41.

The square root of 81673592 is about 9037.3443001802. The cubic root of 81673592 is about 433.8709293604.

The spelling of 81673592 in words is "eighty-one million, six hundred seventy-three thousand, five hundred ninety-two".