81307528032 has 24 divisors (see below), whose sum is σ = 213432261336. Its totient is φ = 27102509312.

The previous prime is 81307528031. The next prime is 81307528069. The reversal of 81307528032 is 23082570318.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×81307528032² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81307528031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 423476613 + ... + 423476804.

It is an arithmetic number, because the mean of its divisors is an integer number (8893010889).

Almost surely, 2^81307528032 is an apocalyptic number.

It is an amenable number.

81307528032 is an abundant number, since it is smaller than the sum of its proper divisors (132124733304).

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

81307528032 is a wasteful number, since it uses less digits than its factorization.

81307528032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 846953430 (or 846953422 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 39.

The spelling of 81307528032 in words is "eighty-one billion, three hundred seven million, five hundred twenty-eight thousand, thirty-two".