81892397605752 has 128 divisors (see below), whose sum is σ = 230299626427200. Its totient is φ = 27296000421120.

The previous prime is 81892397605741. The next prime is 81892397605783. The reversal of 81892397605752 is 25750679329818.

81892397605752 is a `hidden beast` number, since 8 + 1 + 8 + 9 + 2 + 3 + 9 + 7 + 605 + 7 + 5 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 354370948 + ... + 354601964.

Almost surely, 2^{81892397605752} 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 81892397605752, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115149813213600).

81892397605752 is an abundant number, since it is smaller than the sum of its proper divisors (148407228821448).

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

81892397605752 is a wasteful number, since it uses less digits than its factorization.

81892397605752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251305 (or 251283 counting only the distinct ones).

The product of its (nonzero) digits is 457228800, while the sum is 72.

The spelling of 81892397605752 in words is "eighty-one trillion, eight hundred ninety-two billion, three hundred ninety-seven million, six hundred five thousand, seven hundred fifty-two".