688885 has 4 divisors (see below), whose sum is σ = 826668. Its totient is φ = 551104.

The previous prime is 688871. The next prime is 688889. The reversal of 688885 is 588886.

688885 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 108241 + 580644 = 329^2 + 762^2 .

It is a cyclic number.

It is not a de Polignac number, because 688885 - 2⁷ = 688757 is a prime.

It is a Duffinian number.

688885 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688889) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68884 + ... + 68893.

It is an arithmetic number, because the mean of its divisors is an integer number (206667).

2⁶⁸⁸⁸⁸⁵ is an apocalyptic number.

It is an amenable number.

688885 is a deficient number, since it is larger than the sum of its proper divisors (137783).

688885 is a wasteful number, since it uses less digits than its factorization.

688885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137782.

The product of its digits is 122880, while the sum is 43.

The square root of 688885 is about 829.9909638062. The cubic root of 688885 is about 88.3179356888.

Subtracting from 688885 its reverse (588886), we obtain a palindrome (99999).

The spelling of 688885 in words is "six hundred eighty-eight thousand, eight hundred eighty-five".