81404835625536 has 112 divisors (see below), whose sum is σ = 219058412052480. Its totient is φ = 26672081932800.

The previous prime is 81404835625507. The next prime is 81404835625541. The reversal of 81404835625536 is 63552653840418.

It is a self number, because there is not a number n which added to its sum of digits gives 81404835625536.

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 15 ways as a sum of consecutive naturals, for example, 103269885 + ... + 104055171.

It is an arithmetic number, because the mean of its divisors is an integer number (1955878679040).

Almost surely, 2^{81404835625536} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81404835625536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109529206026240).

81404835625536 is an abundant number, since it is smaller than the sum of its proper divisors (137653576426944).

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

81404835625536 is a wasteful number, since it uses less digits than its factorization.

81404835625536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 794512 (or 794502 counting only the distinct ones).

The product of its (nonzero) digits is 82944000, while the sum is 60.

The spelling of 81404835625536 in words is "eighty-one trillion, four hundred four billion, eight hundred thirty-five million, six hundred twenty-five thousand, five hundred thirty-six".