81689358336 has 104 divisors (see below), whose sum is σ = 227282557440. Its totient is φ = 26045792256.

The previous prime is 81689358319. The next prime is 81689358367. The reversal of 81689358336 is 63385398618.

It is a self number, because there is not a number n which added to its sum of digits gives 81689358336.

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, 138105 + ... + 427143.

Almost surely, 2^81689358336 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 81689358336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113641278720).

81689358336 is an abundant number, since it is smaller than the sum of its proper divisors (145593199104).

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

81689358336 is a wasteful number, since it uses less digits than its factorization.

81689358336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289089 (or 289067 counting only the distinct ones).

The product of its digits is 22394880, while the sum is 60.

The spelling of 81689358336 in words is "eighty-one billion, six hundred eighty-nine million, three hundred fifty-eight thousand, three hundred thirty-six".