866786513765999 has 2 divisors, whose sum is σ = 866786513766000. Its totient is φ = 866786513765998.

The previous prime is 866786513765989. The next prime is 866786513766071. The reversal of 866786513765999 is 999567315687668.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-866786513765999 is a prime.

It is a super-2 number, since 2×866786513765999² (a number of 31 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866786513765989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433393256882999 + 433393256883000.

It is an arithmetic number, because the mean of its divisors is an integer number (433393256883000).

Almost surely, 2^{866786513765999} is an apocalyptic number.

866786513765999 is a deficient number, since it is larger than the sum of its proper divisors (1).

866786513765999 is an equidigital number, since it uses as much as digits as its factorization.

866786513765999 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 222213196800, while the sum is 95.

The spelling of 866786513765999 in words is "eight hundred sixty-six trillion, seven hundred eighty-six billion, five hundred thirteen million, seven hundred sixty-five thousand, nine hundred ninety-nine".