684569 has 2 divisors, whose sum is σ = 684570. Its totient is φ = 684568.

The previous prime is 684559. The next prime is 684581. The reversal of 684569 is 965486.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 582169 + 102400 = 763^2 + 320^2 .

It is a cyclic number.

It is not a de Polignac number, because 684569 - 2¹⁶ = 619033 is a prime.

It is a super-2 number, since 2×684569² = 937269431522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (684559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342284 + 342285.

It is an arithmetic number, because the mean of its divisors is an integer number (342285).

2⁶⁸⁴⁵⁶⁹ is an apocalyptic number.

It is an amenable number.

684569 is a deficient number, since it is larger than the sum of its proper divisors (1).

684569 is an equidigital number, since it uses as much as digits as its factorization.

684569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 38.

The square root of 684569 is about 827.3868502702. The cubic root of 684569 is about 88.1331060733.

The spelling of 684569 in words is "six hundred eighty-four thousand, five hundred sixty-nine".