866869 has 2 divisors, whose sum is σ = 866870. Its totient is φ = 866868.

The previous prime is 866857. The next prime is 866909. The reversal of 866869 is 968668.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 580644 + 286225 = 762^2 + 535^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-866869 is a prime.

It is a super-2 number, since 2×866869² = 1502923726322, which contains 22 as substring.

866869 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433434 + 433435.

It is an arithmetic number, because the mean of its divisors is an integer number (433435).

2⁸⁶⁶⁸⁶⁹ is an apocalyptic number.

It is an amenable number.

866869 is a deficient number, since it is larger than the sum of its proper divisors (1).

866869 is an equidigital number, since it uses as much as digits as its factorization.

866869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 43.

The square root of 866869 is about 931.0580003415. The cubic root of 866869 is about 95.3493691816.

The spelling of 866869 in words is "eight hundred sixty-six thousand, eight hundred sixty-nine".