81259392 has 64 divisors (see below), whose sum is σ = 223318800. Its totient is φ = 26148864.

The previous prime is 81259357. The next prime is 81259411. The reversal of 81259392 is 29395218.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 81259392.

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, 7488 + ... + 14784.

Almost surely, 2^81259392 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 81259392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111659400).

81259392 is an abundant number, since it is smaller than the sum of its proper divisors (142059408).

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

81259392 is a wasteful number, since it uses less digits than its factorization.

81259392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7343 (or 7331 counting only the distinct ones).

The product of its digits is 38880, while the sum is 39.

The square root of 81259392 is about 9014.3991480298. The cubic root of 81259392 is about 433.1362406791.

The spelling of 81259392 in words is "eighty-one million, two hundred fifty-nine thousand, three hundred ninety-two".