866786278583689 has 2 divisors, whose sum is σ = 866786278583690. Its totient is φ = 866786278583688.

The previous prime is 866786278583629. The next prime is 866786278583833. The reversal of 866786278583689 is 986385872687668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 585204722910025 + 281581555673664 = 24191005^2 + 16780392^2 .

It is a cyclic number.

It is not a de Polignac number, because 866786278583689 - 2²⁹ = 866785741712777 is a prime.

It is a super-3 number, since 3×866786278583689³ (a number of 46 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 866786278583689.

It is not a weakly prime, because it can be changed into another prime (866786278583629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433393139291844 + 433393139291845.

It is an arithmetic number, because the mean of its divisors is an integer number (433393139291845).

Almost surely, 2^{866786278583689} is an apocalyptic number.

It is an amenable number.

866786278583689 is a deficient number, since it is larger than the sum of its proper divisors (1).

866786278583689 is an equidigital number, since it uses as much as digits as its factorization.

866786278583689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 561842749440, while the sum is 97.

The spelling of 866786278583689 in words is "eight hundred sixty-six trillion, seven hundred eighty-six billion, two hundred seventy-eight million, five hundred eighty-three thousand, six hundred eighty-nine".