866786278588031 has 2 divisors, whose sum is σ = 866786278588032. Its totient is φ = 866786278588030.

The previous prime is 866786278587989. The next prime is 866786278588079. The reversal of 866786278588031 is 130885872687668.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 866786278588031 - 2¹⁰ = 866786278587007 is a prime.

It is a super-2 number, since 2×866786278588031² (a number of 31 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866786278588631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433393139294015 + 433393139294016.

It is an arithmetic number, because the mean of its divisors is an integer number (433393139294016).

Almost surely, 2^{866786278588031} is an apocalyptic number.

866786278588031 is a deficient number, since it is larger than the sum of its proper divisors (1).

866786278588031 is an equidigital number, since it uses as much as digits as its factorization.

866786278588031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10404495360, while the sum is 83.

The spelling of 866786278588031 in words is "eight hundred sixty-six trillion, seven hundred eighty-six billion, two hundred seventy-eight million, five hundred eighty-eight thousand, thirty-one".