866786278380811 has 2 divisors, whose sum is σ = 866786278380812. Its totient is φ = 866786278380810.

The previous prime is 866786278380809. The next prime is 866786278380941. The reversal of 866786278380811 is 118083872687668.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 866786278380811 - 2¹ = 866786278380809 is a prime.

Together with 866786278380809, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (866786278383811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433393139190405 + 433393139190406.

It is an arithmetic number, because the mean of its divisors is an integer number (433393139190406).

Almost surely, 2^{866786278380811} is an apocalyptic number.

866786278380811 is a deficient number, since it is larger than the sum of its proper divisors (1).

866786278380811 is an equidigital number, since it uses as much as digits as its factorization.

866786278380811 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2080899072, while the sum is 79.

The spelling of 866786278380811 in words is "eight hundred sixty-six trillion, seven hundred eighty-six billion, two hundred seventy-eight million, three hundred eighty thousand, eight hundred eleven".