689823 has 16 divisors (see below), whose sum is σ = 1058400. Its totient is φ = 443520.

The previous prime is 689807. The next prime is 689827. The reversal of 689823 is 328986.

It is not a de Polignac number, because 689823 - 2⁴ = 689807 is a prime.

689823 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689827) 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 15 ways as a sum of consecutive naturals, for example, 343 + ... + 1223.

It is an arithmetic number, because the mean of its divisors is an integer number (66150).

2⁶⁸⁹⁸²³ is an apocalyptic number.

689823 is a deficient number, since it is larger than the sum of its proper divisors (368577).

689823 is a wasteful number, since it uses less digits than its factorization.

689823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 919 (or 913 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 689823 is about 830.5558379784. Note that the first 3 decimals coincide. The cubic root of 689823 is about 88.3580026822.

Multiplying 689823 by its sum of digits (36), we get a triangular number (24833628 = T₇₀₄₇).

The spelling of 689823 in words is "six hundred eighty-nine thousand, eight hundred twenty-three".