866659 has 4 divisors (see below), whose sum is σ = 874720. Its totient is φ = 858600.

The previous prime is 866653. The next prime is 866683. The reversal of 866659 is 956668.

866659 is an esthetic number in base 8, because in such base its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 866659 - 2¹³ = 858467 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (866653) 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 in 3 ways as a sum of consecutive naturals, for example, 3867 + ... + 4084.

It is an arithmetic number, because the mean of its divisors is an integer number (218680).

2⁸⁶⁶⁶⁵⁹ is an apocalyptic number.

866659 is a deficient number, since it is larger than the sum of its proper divisors (8061).

866659 is a wasteful number, since it uses less digits than its factorization.

866659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8060.

The product of its digits is 77760, while the sum is 40.

The square root of 866659 is about 930.9452185816. The cubic root of 866659 is about 95.3416690621.

Subtracting 866659 from its reverse (956668), we obtain a palindrome (90009).

The spelling of 866659 in words is "eight hundred sixty-six thousand, six hundred fifty-nine".