866996857 has 2 divisors, whose sum is σ = 866996858. Its totient is φ = 866996856.

The previous prime is 866996813. The next prime is 866996881. The reversal of 866996857 is 758699668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 783384121 + 83612736 = 27989^2 + 9144^2 .

It is a cyclic number.

It is not a de Polignac number, because 866996857 - 2¹¹ = 866994809 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (866996807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433498428 + 433498429.

It is an arithmetic number, because the mean of its divisors is an integer number (433498429).

Almost surely, 2^866996857 is an apocalyptic number.

It is an amenable number.

866996857 is a deficient number, since it is larger than the sum of its proper divisors (1).

866996857 is an equidigital number, since it uses as much as digits as its factorization.

866996857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39191040, while the sum is 64.

The square root of 866996857 is about 29444.8103576844. The cubic root of 866996857 is about 953.5405673528.

The spelling of 866996857 in words is "eight hundred sixty-six million, nine hundred ninety-six thousand, eight hundred fifty-seven".