684913 has 4 divisors (see below), whose sum is σ = 725220. Its totient is φ = 644608.

The previous prime is 684889. The next prime is 684923. The reversal of 684913 is 319486.

684913 is nontrivially palindromic in base 7.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 613089 + 71824 = 783^2 + 268^2 .

It is a cyclic number.

It is not a de Polignac number, because 684913 - 2¹³ = 676721 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684923) 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, 20128 + ... + 20161.

It is an arithmetic number, because the mean of its divisors is an integer number (181305).

2⁶⁸⁴⁹¹³ is an apocalyptic number.

It is an amenable number.

684913 is a deficient number, since it is larger than the sum of its proper divisors (40307).

684913 is a wasteful number, since it uses less digits than its factorization.

684913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40306.

The product of its digits is 5184, while the sum is 31.

The square root of 684913 is about 827.5947075713. The cubic root of 684913 is about 88.1478660715.

It can be divided in two parts, 68 and 4913, that multiplied together give a square (334084 = 578²).

The spelling of 684913 in words is "six hundred eighty-four thousand, nine hundred thirteen".