684920 has 16 divisors (see below), whose sum is σ = 1541160. Its totient is φ = 273952.

The previous prime is 684889. The next prime is 684923. The reversal of 684920 is 29486.

It is an Ulam number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 684920.

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, 8522 + ... + 8601.

2⁶⁸⁴⁹²⁰ is an apocalyptic number.

It is an amenable number.

684920 is an abundant number, since it is smaller than the sum of its proper divisors (856240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

684920 is a wasteful number, since it uses less digits than its factorization.

684920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17134 (or 17130 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 684920 is about 827.5989366837. The cubic root of 684920 is about 88.1481663689.

The spelling of 684920 in words is "six hundred eighty-four thousand, nine hundred twenty".