688820 has 48 divisors (see below), whose sum is σ = 1645056. Its totient is φ = 240000.

The previous prime is 688813. The next prime is 688861. The reversal of 688820 is 28886.

It is a congruent number.

It is an unprimeable number.

688820 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 15 ways as a sum of consecutive naturals, for example, 6770 + ... + 6870.

It is an arithmetic number, because the mean of its divisors is an integer number (34272).

2⁶⁸⁸⁸²⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (822528).

688820 is an abundant number, since it is smaller than the sum of its proper divisors (956236).

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

688820 is a wasteful number, since it uses less digits than its factorization.

688820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 688820 is about 829.9518058297. The cubic root of 688820 is about 88.3151578443.

It can be divided in two parts, 68 and 8820, that added together give a palindrome (8888).

The spelling of 688820 in words is "six hundred eighty-eight thousand, eight hundred twenty".