81810515088 has 60 divisors (see below), whose sum is σ = 232373094928. Its totient is φ = 26863151040.

The previous prime is 81810515081. The next prime is 81810515093. The reversal of 81810515088 is 88051501818.

81810515088 is a `hidden beast` number, since 81 + 8 + 10 + 51 + 508 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (81810515081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4230118 + ... + 4249413.

Almost surely, 2^81810515088 is an apocalyptic number.

It is an amenable number.

81810515088 is an abundant number, since it is smaller than the sum of its proper divisors (150562579840).

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

81810515088 is a wasteful number, since it uses less digits than its factorization.

81810515088 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8479612 (or 8479603 counting only the distinct ones).

The product of its (nonzero) digits is 102400, while the sum is 45.

The spelling of 81810515088 in words is "eighty-one billion, eight hundred ten million, five hundred fifteen thousand, eighty-eight".