866185205487117 has 4 divisors (see below), whose sum is σ = 1154913607316160. Its totient is φ = 577456803658076.

The previous prime is 866185205487079. The next prime is 866185205487157. The reversal of 866185205487117 is 711784502581668.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 866185205487117 - 2¹¹ = 866185205485069 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866185205487157) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 144364200914517 + ... + 144364200914522.

It is an arithmetic number, because the mean of its divisors is an integer number (288728401829040).

Almost surely, 2^{866185205487117} is an apocalyptic number.

It is an amenable number.

866185205487117 is a deficient number, since it is larger than the sum of its proper divisors (288728401829043).

866185205487117 is a wasteful number, since it uses less digits than its factorization.

866185205487117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 288728401829042.

The product of its (nonzero) digits is 180633600, while the sum is 69.

The spelling of 866185205487117 in words is "eight hundred sixty-six trillion, one hundred eighty-five billion, two hundred five million, four hundred eighty-seven thousand, one hundred seventeen".