866831443217161 has 2 divisors, whose sum is σ = 866831443217162. Its totient is φ = 866831443217160.

The previous prime is 866831443217071. The next prime is 866831443217183. The reversal of 866831443217161 is 161712344138668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 723805845249600 + 143025597967561 = 26903640^2 + 11959331^2 .

It is a cyclic number.

It is not a de Polignac number, because 866831443217161 - 2²³ = 866831434828553 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 866831443217161.

It is not a weakly prime, because it can be changed into another prime (866831443217461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433415721608580 + 433415721608581.

It is an arithmetic number, because the mean of its divisors is an integer number (433415721608581).

Almost surely, 2^{866831443217161} is an apocalyptic number.

It is an amenable number.

866831443217161 is a deficient number, since it is larger than the sum of its proper divisors (1).

866831443217161 is an equidigital number, since it uses as much as digits as its factorization.

866831443217161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27869184, while the sum is 61.

The spelling of 866831443217161 in words is "eight hundred sixty-six trillion, eight hundred thirty-one billion, four hundred forty-three million, two hundred seventeen thousand, one hundred sixty-one".