688868 has 6 divisors (see below), whose sum is σ = 1205526. Its totient is φ = 344432.

The previous prime is 688867. The next prime is 688871. The reversal of 688868 is 868886.

It can be written as a sum of positive squares in only one way, i.e., 399424 + 289444 = 632^2 + 538^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 688868.

It is not an unprimeable number, because it can be changed into a prime (688861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86105 + ... + 86112.

It is an arithmetic number, because the mean of its divisors is an integer number (200921).

2⁶⁸⁸⁸⁶⁸ is an apocalyptic number.

It is an amenable number.

688868 is a deficient number, since it is larger than the sum of its proper divisors (516658).

688868 is a wasteful number, since it uses less digits than its factorization.

688868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172221 (or 172219 counting only the distinct ones).

The product of its digits is 147456, while the sum is 44.

The square root of 688868 is about 829.9807226677. The cubic root of 688868 is about 88.3172091925.

The spelling of 688868 in words is "six hundred eighty-eight thousand, eight hundred sixty-eight".