866788215645805 has 32 divisors (see below), whose sum is σ = 1072012189248000. Its totient is φ = 672419165366592.

The previous prime is 866788215645773. The next prime is 866788215645811. The reversal of 866788215645805 is 508546512887668.

It is a cyclic number.

It is not a de Polignac number, because 866788215645805 - 2⁵ = 866788215645773 is a prime.

It is a Smith number, since the sum of its digits (79) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1825706262 + ... + 1826180968.

It is an arithmetic number, because the mean of its divisors is an integer number (33500380914000).

Almost surely, 2^{866788215645805} is an apocalyptic number.

It is an amenable number.

866788215645805 is a deficient number, since it is larger than the sum of its proper divisors (205223973602195).

866788215645805 is a wasteful number, since it uses less digits than its factorization.

866788215645805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535993.

The product of its (nonzero) digits is 6193152000, while the sum is 79.

The spelling of 866788215645805 in words is "eight hundred sixty-six trillion, seven hundred eighty-eight billion, two hundred fifteen million, six hundred forty-five thousand, eight hundred five".