666223 has 4 divisors (see below), whose sum is σ = 670248. Its totient is φ = 662200.

The previous prime is 666203. The next prime is 666229. The reversal of 666223 is 322666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 322666 = 2 ⋅161333.

It is a cyclic number.

It is not a de Polignac number, because 666223 - 2⁵ = 666191 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 (666229) 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, 1753 + ... + 2098.

It is an arithmetic number, because the mean of its divisors is an integer number (167562).

2⁶⁶⁶²²³ is an apocalyptic number.

666223 is a deficient number, since it is larger than the sum of its proper divisors (4025).

666223 is a wasteful number, since it uses less digits than its factorization.

666223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4024.

The product of its digits is 2592, while the sum is 25.

The square root of 666223 is about 816.2248464731. The cubic root of 666223 is about 87.3386632465.

Adding to 666223 its reverse (322666), we get a palindrome (988889).

The spelling of 666223 in words is "six hundred sixty-six thousand, two hundred twenty-three".