684565 has 8 divisors (see below), whose sum is σ = 938880. Its totient is φ = 469392.

The previous prime is 684559. The next prime is 684569. The reversal of 684565 is 565486.

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

It is not a de Polignac number, because 684565 - 2³ = 684557 is a prime.

684565 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 684565.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684569) 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, 9745 + ... + 9814.

It is an arithmetic number, because the mean of its divisors is an integer number (117360).

2⁶⁸⁴⁵⁶⁵ is an apocalyptic number.

It is an amenable number.

684565 is a deficient number, since it is larger than the sum of its proper divisors (254315).

684565 is a wasteful number, since it uses less digits than its factorization.

684565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19571.

The product of its digits is 28800, while the sum is 34.

The square root of 684565 is about 827.3844330177. The cubic root of 684565 is about 88.1329344163.

The spelling of 684565 in words is "six hundred eighty-four thousand, five hundred sixty-five".