688438 has 8 divisors (see below), whose sum is σ = 1042632. Its totient is φ = 340896.

The previous prime is 688433. The next prime is 688447. The reversal of 688438 is 834886.

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

It is a junction number, because it is equal to n+sod(n) for n = 688397 and 688406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688433) by changing a digit.

688438 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1395 + ... + 1822.

It is an arithmetic number, because the mean of its divisors is an integer number (130329).

2⁶⁸⁸⁴³⁸ is an apocalyptic number.

688438 is a deficient number, since it is larger than the sum of its proper divisors (354194).

688438 is a wasteful number, since it uses less digits than its factorization.

688438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3326.

The product of its digits is 36864, while the sum is 37.

The square root of 688438 is about 829.7216400697. The cubic root of 688438 is about 88.2988291330.

The spelling of 688438 in words is "six hundred eighty-eight thousand, four hundred thirty-eight".