866699 has 4 divisors (see below), whose sum is σ = 887880. Its totient is φ = 845520.

The previous prime is 866693. The next prime is 866707. The reversal of 866699 is 996668.

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 866699 - 2⁴ = 866683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (866693) 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, 10529 + ... + 10610.

It is an arithmetic number, because the mean of its divisors is an integer number (221970).

2⁸⁶⁶⁶⁹⁹ is an apocalyptic number.

866699 is a deficient number, since it is larger than the sum of its proper divisors (21181).

866699 is a wasteful number, since it uses less digits than its factorization.

866699 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21180.

The product of its digits is 139968, while the sum is 44.

The square root of 866699 is about 930.9667018750. The cubic root of 866699 is about 95.3431358474.

The spelling of 866699 in words is "eight hundred sixty-six thousand, six hundred ninety-nine".