685408 has 12 divisors (see below), whose sum is σ = 1349460. Its totient is φ = 342688.

The previous prime is 685393. The next prime is 685417. The reversal of 685408 is 804586.

It is a self number, because there is not a number n which added to its sum of digits gives 685408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10678 + ... + 10741.

It is an arithmetic number, because the mean of its divisors is an integer number (112455).

2⁶⁸⁵⁴⁰⁸ is an apocalyptic number.

It is an amenable number.

685408 is a deficient number, since it is larger than the sum of its proper divisors (664052).

685408 is a wasteful number, since it uses less digits than its factorization.

685408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21429 (or 21421 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 685408 is about 827.8937129849. The cubic root of 685408 is about 88.1690963525.

It can be divided in two parts, 68 and 5408, that added together give a square (5476 = 74²).

The spelling of 685408 in words is "six hundred eighty-five thousand, four hundred eight".