81102115566 has 24 divisors (see below), whose sum is σ = 182229445944. Its totient is φ = 27034038360.

The previous prime is 81102115561. The next prime is 81102115571. The reversal of 81102115566 is 66551120118.

81102115566 is a `hidden beast` number, since 81 + 1 + 0 + 2 + 1 + 15 + 566 = 666.

It is an interprime number because it is at equal distance from previous prime (81102115561) and next prime (81102115571).

It is a self number, because there is not a number n which added to its sum of digits gives 81102115566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81102115561) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 83437905 + ... + 83438876.

It is an arithmetic number, because the mean of its divisors is an integer number (7592893581).

Almost surely, 2^81102115566 is an apocalyptic number.

81102115566 is an abundant number, since it is smaller than the sum of its proper divisors (101127330378).

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

81102115566 is a wasteful number, since it uses less digits than its factorization.

81102115566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166876798 (or 166876786 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 36.

The spelling of 81102115566 in words is "eighty-one billion, one hundred two million, one hundred fifteen thousand, five hundred sixty-six".