81575089536 has 64 divisors (see below), whose sum is σ = 218013347520. Its totient is φ = 27024855552.

The previous prime is 81575089523. The next prime is 81575089591. The reversal of 81575089536 is 63598057518.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

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, 589050 + ... + 714233.

It is an arithmetic number, because the mean of its divisors is an integer number (3406458555).

Almost surely, 2^81575089536 is an apocalyptic number.

It is an amenable number.

81575089536 is an abundant number, since it is smaller than the sum of its proper divisors (136438257984).

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

81575089536 is a wasteful number, since it uses less digits than its factorization.

81575089536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1303463 (or 1303451 counting only the distinct ones).

The product of its (nonzero) digits is 9072000, while the sum is 57.

The spelling of 81575089536 in words is "eighty-one billion, five hundred seventy-five million, eighty-nine thousand, five hundred thirty-six".