688440660 has 24 divisors (see below), whose sum is σ = 1927634016. Its totient is φ = 183584160.

The previous prime is 688440617. The next prime is 688440679. The reversal of 688440660 is 66044886.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 5736946 + ... + 5737065.

It is an arithmetic number, because the mean of its divisors is an integer number (80318084).

Almost surely, 2^688440660 is an apocalyptic number.

688440660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

688440660 is an abundant number, since it is smaller than the sum of its proper divisors (1239193356).

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

688440660 is a wasteful number, since it uses less digits than its factorization.

688440660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11474023 (or 11474021 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 42.

The square root of 688440660 is about 26238.1527551007. The cubic root of 688440660 is about 882.9894285644.

The spelling of 688440660 in words is "six hundred eighty-eight million, four hundred forty thousand, six hundred sixty".