688668844 has 24 divisors (see below), whose sum is σ = 1317230208. Its totient is φ = 313624320.

The previous prime is 688668809. The next prime is 688668859. The reversal of 688668844 is 448866886.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161239 + ... + 165454.

It is an arithmetic number, because the mean of its divisors is an integer number (54884592).

Almost surely, 2^688668844 is an apocalyptic number.

It is an amenable number.

688668844 is a deficient number, since it is larger than the sum of its proper divisors (628561364).

688668844 is a wasteful number, since it uses less digits than its factorization.

688668844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 326745 (or 326743 counting only the distinct ones).

The product of its digits is 14155776, while the sum is 58.

The square root of 688668844 is about 26242.5007192531. The cubic root of 688668844 is about 883.0869735502.

The spelling of 688668844 in words is "six hundred eighty-eight million, six hundred sixty-eight thousand, eight hundred forty-four".