688818 has 16 divisors (see below), whose sum is σ = 1483776. Its totient is φ = 211920.

The previous prime is 688813. The next prime is 688861. The reversal of 688818 is 818886.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 688818.

It is not an unprimeable number, because it can be changed into a prime (688813) by changing a digit.

688818 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 7 ways as a sum of consecutive naturals, for example, 4338 + ... + 4493.

It is an arithmetic number, because the mean of its divisors is an integer number (92736).

2⁶⁸⁸⁸¹⁸ is an apocalyptic number.

688818 is an abundant number, since it is smaller than the sum of its proper divisors (794958).

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

688818 is a wasteful number, since it uses less digits than its factorization.

688818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8849.

The product of its digits is 24576, while the sum is 39.

The square root of 688818 is about 829.9506009396. The cubic root of 688818 is about 88.3150723693.

The spelling of 688818 in words is "six hundred eighty-eight thousand, eight hundred eighteen".