866800082636861 has 2 divisors, whose sum is σ = 866800082636862. Its totient is φ = 866800082636860.

The previous prime is 866800082636857. The next prime is 866800082636879. The reversal of 866800082636861 is 168636280008668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 628332179568025 + 238467903068836 = 25066555^2 + 15442406^2 .

It is a cyclic number.

It is not a de Polignac number, because 866800082636861 - 2² = 866800082636857 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 866800082636791 and 866800082636800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866800082836861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433400041318430 + 433400041318431.

It is an arithmetic number, because the mean of its divisors is an integer number (433400041318431).

Almost surely, 2^{866800082636861} is an apocalyptic number.

It is an amenable number.

866800082636861 is a deficient number, since it is larger than the sum of its proper divisors (1).

866800082636861 is an equidigital number, since it uses as much as digits as its factorization.

866800082636861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 191102976, while the sum is 68.

The spelling of 866800082636861 in words is "eight hundred sixty-six trillion, eight hundred billion, eighty-two million, six hundred thirty-six thousand, eight hundred sixty-one".