688496640 has 224 divisors, whose sum is σ = 2378025216. Its totient is φ = 169082880.

The previous prime is 688496609. The next prime is 688496657. The reversal of 688496640 is 46694886.

It is an unprimeable 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 15 ways as a sum of consecutive naturals, for example, 1597225 + ... + 1597655.

It is an arithmetic number, because the mean of its divisors is an integer number (10616184).

Almost surely, 2^688496640 is an apocalyptic number.

688496640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688496640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1189012608).

688496640 is an abundant number, since it is smaller than the sum of its proper divisors (1689528576).

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

688496640 is a wasteful number, since it uses less digits than its factorization.

688496640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478 (or 454 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 51.

The square root of 688496640 is about 26239.2195005873. The cubic root of 688496640 is about 883.0133611081.

The spelling of 688496640 in words is "six hundred eighty-eight million, four hundred ninety-six thousand, six hundred forty".