81593869912 has 8 divisors (see below), whose sum is σ = 152988506100. Its totient is φ = 40796934952.

The previous prime is 81593869897. The next prime is 81593869969. The reversal of 81593869912 is 21996839518.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5099616862 + ... + 5099616877.

Almost surely, 2^81593869912 is an apocalyptic number.

It is an amenable number.

81593869912 is a deficient number, since it is larger than the sum of its proper divisors (71394636188).

81593869912 is a wasteful number, since it uses less digits than its factorization.

81593869912 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10199233745 (or 10199233741 counting only the distinct ones).

The product of its digits is 8398080, while the sum is 61.

The spelling of 81593869912 in words is "eighty-one billion, five hundred ninety-three million, eight hundred sixty-nine thousand, nine hundred twelve".