688964 has 12 divisors (see below), whose sum is σ = 1235388. Its totient is φ = 336000.

The previous prime is 688957. The next prime is 688969. The reversal of 688964 is 469886.

It can be written as a sum of positive squares in 2 ways, for example, as 36100 + 652864 = 190^2 + 808^2 .

It is a Harshad number since it is a multiple of its sum of digits (41).

It is not an unprimeable number, because it can be changed into a prime (688969) by changing a digit.

688964 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1937 + ... + 2264.

It is an arithmetic number, because the mean of its divisors is an integer number (102949).

2⁶⁸⁸⁹⁶⁴ is an apocalyptic number.

It is an amenable number.

688964 is a deficient number, since it is larger than the sum of its proper divisors (546424).

688964 is a wasteful number, since it uses less digits than its factorization.

688964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4246 (or 4244 counting only the distinct ones).

The product of its digits is 82944, while the sum is 41.

The square root of 688964 is about 830.0385533215. The cubic root of 688964 is about 88.3213116032.

It can be divided in two parts, 6889 and 64, that multiplied together give a square (440896 = 664²).

The spelling of 688964 in words is "six hundred eighty-eight thousand, nine hundred sixty-four".