684939 has 8 divisors (see below), whose sum is σ = 918160. Its totient is φ = 454176.

The previous prime is 684923. The next prime is 684949. The reversal of 684939 is 939486.

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

It is not a de Polignac number, because 684939 - 2⁴ = 684923 is a prime.

It is a Duffinian number.

684939 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 684897 and 684906.

It is not an unprimeable number, because it can be changed into a prime (684949) 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 7 ways as a sum of consecutive naturals, for example, 189 + ... + 1185.

It is an arithmetic number, because the mean of its divisors is an integer number (114770).

2⁶⁸⁴⁹³⁹ is an apocalyptic number.

684939 is a deficient number, since it is larger than the sum of its proper divisors (233221).

684939 is a wasteful number, since it uses less digits than its factorization.

684939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1229.

The product of its digits is 46656, while the sum is 39.

The square root of 684939 is about 827.6104155942. The cubic root of 684939 is about 88.1489814518.

The spelling of 684939 in words is "six hundred eighty-four thousand, nine hundred thirty-nine".