81108681 has 8 divisors (see below), whose sum is σ = 108196704. Its totient is φ = 54046560.

The previous prime is 81108667. The next prime is 81108697. The reversal of 81108681 is 18680118.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81108681 - 2¹⁷ = 80977609 is a prime.

It is a super-2 number, since 2×81108681² = 13157236267119522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81108631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2686 + ... + 13016.

It is an arithmetic number, because the mean of its divisors is an integer number (13524588).

Almost surely, 2^81108681 is an apocalyptic number.

It is an amenable number.

81108681 is a deficient number, since it is larger than the sum of its proper divisors (27088023).

81108681 is a wasteful number, since it uses less digits than its factorization.

81108681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12951.

The product of its (nonzero) digits is 3072, while the sum is 33.

The square root of 81108681 is about 9006.0358093892. The cubic root of 81108681 is about 432.8682971095.

Adding to 81108681 its reverse (18680118), we get a palindrome (99788799).

The spelling of 81108681 in words is "eighty-one million, one hundred eight thousand, six hundred eighty-one".