669823 has 8 divisors (see below), whose sum is σ = 835200. Its totient is φ = 521880.

The previous prime is 669791. The next prime is 669839. The reversal of 669823 is 328966.

669823 = T₂₄₂ + T₂₄₃ + ... + T₂₆₂.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 669823 - 2⁵ = 669791 is a prime.

It is a Duffinian number.

669823 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4273 + ... + 4426.

It is an arithmetic number, because the mean of its divisors is an integer number (104400).

2⁶⁶⁹⁸²³ is an apocalyptic number.

669823 is a deficient number, since it is larger than the sum of its proper divisors (165377).

669823 is a wasteful number, since it uses less digits than its factorization.

669823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8717.

The product of its digits is 15552, while the sum is 34.

The square root of 669823 is about 818.4271500873. The cubic root of 669823 is about 87.4956950263.

It can be divided in two parts, 66 and 9823, that added together give a palindrome (9889).

The spelling of 669823 in words is "six hundred sixty-nine thousand, eight hundred twenty-three".