866023 has 4 divisors (see below), whose sum is σ = 867888. Its totient is φ = 864160.

The previous prime is 866011. The next prime is 866029. The reversal of 866023 is 320668.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 866023 - 2⁹ = 865511 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 390 + ... + 1372.

It is an arithmetic number, because the mean of its divisors is an integer number (216972).

2⁸⁶⁶⁰²³ is an apocalyptic number.

866023 is a deficient number, since it is larger than the sum of its proper divisors (1865).

866023 is an equidigital number, since it uses as much as digits as its factorization.

866023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1864.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 866023 is about 930.6035675840. The cubic root of 866023 is about 95.3183411094.

The spelling of 866023 in words is "eight hundred sixty-six thousand, twenty-three".