81590099328 has 144 divisors (see below), whose sum is σ = 242605291500. Its totient is φ = 26319029760.

The previous prime is 81590099309. The next prime is 81590099341. The reversal of 81590099328 is 82399009518.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1070223 + ... + 1143921.

Almost surely, 2^81590099328 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 81590099328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121302645750).

81590099328 is an abundant number, since it is smaller than the sum of its proper divisors (161015192172).

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

81590099328 is a wasteful number, since it uses less digits than its factorization.

81590099328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73781 (or 73735 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 54.

The spelling of 81590099328 in words is "eighty-one billion, five hundred ninety million, ninety-nine thousand, three hundred twenty-eight".