688628868 has 12 divisors (see below), whose sum is σ = 1606800720. Its totient is φ = 229542952.

The previous prime is 688628861. The next prime is 688628873. The reversal of 688628868 is 868826886.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×688628868² = 948419435685922848, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (688628861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28692858 + ... + 28692881.

It is an arithmetic number, because the mean of its divisors is an integer number (133900060).

Almost surely, 2^688628868 is an apocalyptic number.

It is an amenable number.

688628868 is an abundant number, since it is smaller than the sum of its proper divisors (918171852).

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

688628868 is a wasteful number, since it uses less digits than its factorization.

688628868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57385746 (or 57385744 counting only the distinct ones).

The product of its digits is 14155776, while the sum is 60.

The square root of 688628868 is about 26241.7390429827. The cubic root of 688628868 is about 883.0698860109.

The spelling of 688628868 in words is "six hundred eighty-eight million, six hundred twenty-eight thousand, eight hundred sixty-eight".