684931 has 16 divisors (see below), whose sum is σ = 806400. Its totient is φ = 576288.

The previous prime is 684923. The next prime is 684949. The reversal of 684931 is 139486.

684931 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 684931 - 2³ = 684923 is a prime.

It is a super-2 number, since 2×684931² = 938260949522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 684893 and 684902.

It is not an unprimeable number, because it can be changed into a prime (684961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11580 + ... + 11638.

It is an arithmetic number, because the mean of its divisors is an integer number (50400).

2⁶⁸⁴⁹³¹ is an apocalyptic number.

684931 is a deficient number, since it is larger than the sum of its proper divisors (121469).

684931 is a wasteful number, since it uses less digits than its factorization.

684931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138.

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

The square root of 684931 is about 827.6055823881. The cubic root of 684931 is about 88.1486382609.

It can be divided in two parts, 684 and 931, that multiplied together give a square (636804 = 798²).

The spelling of 684931 in words is "six hundred eighty-four thousand, nine hundred thirty-one".