81502113312 has 288 divisors, whose sum is σ = 248606886528. Its totient is φ = 25265737728.

The previous prime is 81502113311. The next prime is 81502113323. The reversal of 81502113312 is 21331120518.

It is a tau number, because it is divible by the number of its divisors (288).

It is not an unprimeable number, because it can be changed into a prime (81502113311) 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 47 ways as a sum of consecutive naturals, for example, 78897948 + ... + 78898980.

It is an arithmetic number, because the mean of its divisors is an integer number (863218356).

Almost surely, 2^81502113312 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 81502113312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124303443264).

81502113312 is an abundant number, since it is smaller than the sum of its proper divisors (167104773216).

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

81502113312 is a wasteful number, since it uses less digits than its factorization.

81502113312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1392 (or 1381 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The spelling of 81502113312 in words is "eighty-one billion, five hundred two million, one hundred thirteen thousand, three hundred twelve".