81522237840756 has 12 divisors (see below), whose sum is σ = 190218554961792. Its totient is φ = 27174079280248.

The previous prime is 81522237840731. The next prime is 81522237840779. The reversal of 81522237840756 is 65704873222518.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 81522237840756.

It is a congruent number.

It is an unprimeable number.

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, 3396759910020 + ... + 3396759910043.

It is an arithmetic number, because the mean of its divisors is an integer number (15851546246816).

Almost surely, 2^{81522237840756} is an apocalyptic number.

It is an amenable number.

81522237840756 is an abundant number, since it is smaller than the sum of its proper divisors (108696317121036).

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

81522237840756 is a wasteful number, since it uses less digits than its factorization.

81522237840756 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6793519820070 (or 6793519820068 counting only the distinct ones).

The product of its (nonzero) digits is 45158400, while the sum is 60.

The spelling of 81522237840756 in words is "eighty-one trillion, five hundred twenty-two billion, two hundred thirty-seven million, eight hundred forty thousand, seven hundred fifty-six".