81120215836 has 96 divisors (see below), whose sum is σ = 168763392000. Its totient is φ = 33707275200.

The previous prime is 81120215801. The next prime is 81120215843. The reversal of 81120215836 is 63851202118.

It is a junction number, because it is equal to n+sod(n) for n = 81120215795 and 81120215804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9299485 + ... + 9308203.

It is an arithmetic number, because the mean of its divisors is an integer number (1757952000).

Almost surely, 2^81120215836 is an apocalyptic number.

It is an amenable number.

81120215836 is an abundant number, since it is smaller than the sum of its proper divisors (87643176164).

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

81120215836 is a wasteful number, since it uses less digits than its factorization.

81120215836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9143 (or 9141 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 37.

The spelling of 81120215836 in words is "eighty-one billion, one hundred twenty million, two hundred fifteen thousand, eight hundred thirty-six".