684406 has 4 divisors (see below), whose sum is σ = 1026612. Its totient is φ = 342202.

The previous prime is 684379. The next prime is 684407. The reversal of 684406 is 604486.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684407) by changing a digit.

684406 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 171100 + ... + 171103.

It is an arithmetic number, because the mean of its divisors is an integer number (256653).

2⁶⁸⁴⁴⁰⁶ is an apocalyptic number.

684406 is a deficient number, since it is larger than the sum of its proper divisors (342206).

684406 is a wasteful number, since it uses less digits than its factorization.

684406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342205.

The product of its (nonzero) digits is 4608, while the sum is 28.

The square root of 684406 is about 827.2883415110. The cubic root of 684406 is about 88.1261105103.

The spelling of 684406 in words is "six hundred eighty-four thousand, four hundred six".