81859665923392 has 224 divisors, whose sum is σ = 190084812819200. Its totient is φ = 34962518384640.

The previous prime is 81859665923351. The next prime is 81859665923471. The reversal of 81859665923392 is 29332956695818.

It is a tau number, because it is divible by the number of its divisors (224).

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, 8858307892 + ... + 8858317132.

Almost surely, 2^{81859665923392} 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 81859665923392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95042406409600).

81859665923392 is an abundant number, since it is smaller than the sum of its proper divisors (108225146895808).

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

81859665923392 is an equidigital number, since it uses as much as digits as its factorization.

81859665923392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10614 (or 10590 counting only the distinct ones).

The product of its digits is 1511654400, while the sum is 76.

The spelling of 81859665923392 in words is "eighty-one trillion, eight hundred fifty-nine billion, six hundred sixty-five million, nine hundred twenty-three thousand, three hundred ninety-two".