866786517712161 has 12 divisors (see below), whose sum is σ = 1252025593371540. Its totient is φ = 577857390778080.

The previous prime is 866786517712133. The next prime is 866786517712187. The reversal of 866786517712161 is 161217715687668.

866786517712161 is a `hidden beast` number, since 8 + 6 + 6 + 7 + 86 + 517 + 7 + 1 + 21 + 6 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 397673153761536 + 469113363950625 = 19941744^2 + 21659025^2 .

It is not a de Polignac number, because 866786517712161 - 2¹⁰ = 866786517711137 is a prime.

It is a hoax number, since the sum of its digits (72) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 866786517712161.

It is not an unprimeable number, because it can be changed into a prime (866786517712111) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4019130 + ... + 41829731.

It is an arithmetic number, because the mean of its divisors is an integer number (104335466114295).

Almost surely, 2^{866786517712161} is an apocalyptic number.

It is an amenable number.

866786517712161 is a deficient number, since it is larger than the sum of its proper divisors (385239075659379).

866786517712161 is a wasteful number, since it uses less digits than its factorization.

866786517712161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47949456 (or 47949453 counting only the distinct ones).

The product of its digits is 284497920, while the sum is 72.

The spelling of 866786517712161 in words is "eight hundred sixty-six trillion, seven hundred eighty-six billion, five hundred seventeen million, seven hundred twelve thousand, one hundred sixty-one".