81926256384 has 1134 divisors, whose sum is σ = 312755007264. Its totient is φ = 21319925760.

The previous prime is 81926256383. The next prime is 81926256407. The reversal of 81926256384 is 48365262918.

81926256384 is a `hidden beast` number, since 8 + 1 + 9 + 2 + 6 + 256 + 384 = 666.

It is a tau number, because it is divible by the number of its divisors (1134).

It is a super-2 number, since 2×81926256384² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

Its product of digits (4976640) is a multiple of the sum of its prime divisors (60).

It is a self number, because there is not a number n which added to its sum of digits gives 81926256384.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81926256383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 125 ways as a sum of consecutive naturals, for example, 2642782449 + ... + 2642782479.

Almost surely, 2^81926256384 is an apocalyptic number.

81926256384 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81926256384, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156377503632).

81926256384 is an abundant number, since it is smaller than the sum of its proper divisors (230828750880).

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

81926256384 is an equidigital number, since it uses as much as digits as its factorization.

81926256384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113 (or 60 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 54.

The spelling of 81926256384 in words is "eighty-one billion, nine hundred twenty-six million, two hundred fifty-six thousand, three hundred eighty-four".