866909 has 2 divisors, whose sum is σ = 866910. Its totient is φ = 866908.

The previous prime is 866869. The next prime is 866917. The reversal of 866909 is 909668.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 828100 + 38809 = 910^2 + 197^2 .

It is a cyclic number.

It is not a de Polignac number, because 866909 - 2⁸ = 866653 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (866969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 433454 + 433455.

It is an arithmetic number, because the mean of its divisors is an integer number (433455).

2⁸⁶⁶⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

866909 is a deficient number, since it is larger than the sum of its proper divisors (1).

866909 is an equidigital number, since it uses as much as digits as its factorization.

866909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 866909 is about 931.0794810326. The cubic root of 866909 is about 95.3508357300.

The spelling of 866909 in words is "eight hundred sixty-six thousand, nine hundred nine".