80810861 has 2 divisors, whose sum is σ = 80810862. Its totient is φ = 80810860.

The previous prime is 80810839. The next prime is 80810867. The reversal of 80810861 is 16801808.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42445225 + 38365636 = 6515^2 + 6194^2 .

It is a cyclic number.

It is not a de Polignac number, because 80810861 - 2¹⁸ = 80548717 is a prime.

It is a super-2 number, since 2×80810861² = 13060790511122642, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80810867) 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 as a sum of consecutive naturals, namely, 40405430 + 40405431.

It is an arithmetic number, because the mean of its divisors is an integer number (40405431).

Almost surely, 2^80810861 is an apocalyptic number.

It is an amenable number.

80810861 is a deficient number, since it is larger than the sum of its proper divisors (1).

80810861 is an equidigital number, since it uses as much as digits as its factorization.

80810861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3072, while the sum is 32.

The square root of 80810861 is about 8989.4861365931. The cubic root of 80810861 is about 432.3378362280.

The spelling of 80810861 in words is "eighty million, eight hundred ten thousand, eight hundred sixty-one".