866767811531 has 2 divisors, whose sum is σ = 866767811532. Its totient is φ = 866767811530.

The previous prime is 866767811521. The next prime is 866767811549. The reversal of 866767811531 is 135118767668.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 866767811531 - 2¹⁸ = 866767549387 is a prime.

It is a super-2 number, since 2×866767811531² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (866767811521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433383905765 + 433383905766.

It is an arithmetic number, because the mean of its divisors is an integer number (433383905766).

Almost surely, 2^866767811531 is an apocalyptic number.

866767811531 is a deficient number, since it is larger than the sum of its proper divisors (1).

866767811531 is an equidigital number, since it uses as much as digits as its factorization.

866767811531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10160640, while the sum is 59.

The spelling of 866767811531 in words is "eight hundred sixty-six billion, seven hundred sixty-seven million, eight hundred eleven thousand, five hundred thirty-one".