81633986896 has 160 divisors (see below), whose sum is σ = 205579984896. Its totient is φ = 30473280000.

The previous prime is 81633986869. The next prime is 81633986909. The reversal of 81633986896 is 69868933618.

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, 3846811 + ... + 3867973.

Almost surely, 2^81633986896 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 81633986896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102789992448).

81633986896 is an abundant number, since it is smaller than the sum of its proper divisors (123945998000).

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

81633986896 is a wasteful number, since it uses less digits than its factorization.

81633986896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21321 (or 21315 counting only the distinct ones).

The product of its digits is 80621568, while the sum is 67.

The spelling of 81633986896 in words is "eighty-one billion, six hundred thirty-three million, nine hundred eighty-six thousand, eight hundred ninety-six".