688928 has 12 divisors (see below), whose sum is σ = 1356390. Its totient is φ = 344448.

The previous prime is 688907. The next prime is 688939. The reversal of 688928 is 829886.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 659344 + 29584 = 812^2 + 172^2 .

It is a nialpdrome in base 16.

It is an unprimeable number.

688928 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 as a sum of consecutive naturals, namely, 10733 + ... + 10796.

2⁶⁸⁸⁹²⁸ is an apocalyptic number.

It is an amenable number.

688928 is a deficient number, since it is larger than the sum of its proper divisors (667462).

688928 is a wasteful number, since it uses less digits than its factorization.

688928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21539 (or 21531 counting only the distinct ones).

The product of its digits is 55296, while the sum is 41.

The square root of 688928 is about 830.0168672985. The cubic root of 688928 is about 88.3197732438.

The spelling of 688928 in words is "six hundred eighty-eight thousand, nine hundred twenty-eight".