81110081 has 8 divisors (see below), whose sum is σ = 88546920. Its totient is φ = 73844352.

The previous prime is 81110059. The next prime is 81110101. The reversal of 81110081 is 18001118.

It can be written as a sum of positive squares in 4 ways, for example, as 18447025 + 62663056 = 4295^2 + 7916^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81110081 is a prime.

It is a super-2 number, since 2×81110081² = 13157690479653122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81110041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41786 + ... + 43683.

It is an arithmetic number, because the mean of its divisors is an integer number (11068365).

Almost surely, 2^81110081 is an apocalyptic number.

It is an amenable number.

81110081 is a deficient number, since it is larger than the sum of its proper divisors (7436839).

81110081 is a wasteful number, since it uses less digits than its factorization.

81110081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85555.

The product of its (nonzero) digits is 64, while the sum is 20.

The square root of 81110081 is about 9006.1135347052. The cubic root of 81110081 is about 432.8707876449.

Adding to 81110081 its reverse (18001118), we get a palindrome (99111199).

The spelling of 81110081 in words is "eighty-one million, one hundred ten thousand, eighty-one".