81092681 has 2 divisors, whose sum is σ = 81092682. Its totient is φ = 81092680.

The previous prime is 81092677. The next prime is 81092717. The reversal of 81092681 is 18629018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75255625 + 5837056 = 8675^2 + 2416^2 .

It is a cyclic number.

It is not a de Polignac number, because 81092681 - 2² = 81092677 is a prime.

It is a super-2 number, since 2×81092681² = 13152045823535522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (81092651) 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 as a sum of consecutive naturals, namely, 40546340 + 40546341.

It is an arithmetic number, because the mean of its divisors is an integer number (40546341).

Almost surely, 2^81092681 is an apocalyptic number.

It is an amenable number.

81092681 is a deficient number, since it is larger than the sum of its proper divisors (1).

81092681 is an equidigital number, since it uses as much as digits as its factorization.

81092681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 35.

The square root of 81092681 is about 9005.1474724182. The cubic root of 81092681 is about 432.8398318119.

The spelling of 81092681 in words is "eighty-one million, ninety-two thousand, six hundred eighty-one".