81398036928 has 224 divisors, whose sum is σ = 242122350400. Its totient is φ = 23967498240.

The previous prime is 81398036879. The next prime is 81398036959. The reversal of 81398036928 is 82963089318.

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, 5626248 + ... + 5640696.

It is an arithmetic number, because the mean of its divisors is an integer number (1080903350).

Almost surely, 2^81398036928 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 81398036928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121061175200).

81398036928 is an abundant number, since it is smaller than the sum of its proper divisors (160724313472).

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

81398036928 is a wasteful number, since it uses less digits than its factorization.

81398036928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14575 (or 14565 counting only the distinct ones).

The product of its (nonzero) digits is 4478976, while the sum is 57.

The spelling of 81398036928 in words is "eighty-one billion, three hundred ninety-eight million, thirty-six thousand, nine hundred twenty-eight".