81069638565888 has 360 divisors, whose sum is σ = 279415244925600. Its totient is φ = 23162747682816.

The previous prime is 81069638565863. The next prime is 81069638565893. The reversal of 81069638565888 is 88856583696018.

81069638565888 is a `hidden beast` number, since 8 + 10 + 6 + 9 + 6 + 38 + 565 + 8 + 8 + 8 = 666.

It is a zygodrome in base 8.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19806003 + ... + 23546061.

Almost surely, 2^{81069638565888} 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 81069638565888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139707622462800).

81069638565888 is an abundant number, since it is smaller than the sum of its proper divisors (198345606359712).

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

81069638565888 is an equidigital number, since it uses as much as digits as its factorization.

81069638565888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3740110 (or 3740071 counting only the distinct ones).

The product of its (nonzero) digits is 4777574400, while the sum is 81.

The spelling of 81069638565888 in words is "eighty-one trillion, sixty-nine billion, six hundred thirty-eight million, five hundred sixty-five thousand, eight hundred eighty-eight".