81206604752 has 60 divisors (see below), whose sum is σ = 197104517316. Its totient is φ = 32125685760.

The previous prime is 81206604719. The next prime is 81206604763. The reversal of 81206604752 is 25740660218.

It can be written as a sum of positive squares in 2 ways, for example, as 24001445776 + 57205158976 = 154924^2 + 239176^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3973649 + ... + 3994032.

Almost surely, 2^81206604752 is an apocalyptic number.

It is an amenable number.

81206604752 is an abundant number, since it is smaller than the sum of its proper divisors (115897912564).

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

81206604752 is a wasteful number, since it uses less digits than its factorization.

81206604752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7967716 (or 7967703 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 41.

The spelling of 81206604752 in words is "eighty-one billion, two hundred six million, six hundred four thousand, seven hundred fifty-two".