688340 has 24 divisors (see below), whose sum is σ = 1462272. Its totient is φ = 272160.

The previous prime is 688339. The next prime is 688357. The reversal of 688340 is 43886.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2405 + ... + 2675.

It is an arithmetic number, because the mean of its divisors is an integer number (60928).

2⁶⁸⁸³⁴⁰ is an apocalyptic number.

It is an amenable number.

688340 is an abundant number, since it is smaller than the sum of its proper divisors (773932).

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

688340 is a wasteful number, since it uses less digits than its factorization.

688340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407 (or 405 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 688340 is about 829.6625820175. The cubic root of 688340 is about 88.2946391184.

The spelling of 688340 in words is "six hundred eighty-eight thousand, three hundred forty".