688687680 has 224 divisors, whose sum is σ = 2438156160. Its totient is φ = 163676160.

The previous prime is 688687667. The next prime is 688687687. The reversal of 688687680 is 86786886.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a self number, because there is not a number n which added to its sum of digits gives 688687680.

It is not an unprimeable number, because it can be changed into a prime (688687687) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 308970 + ... + 311190.

Almost surely, 2^688687680 is an apocalyptic number.

688687680 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 688687680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1219078080).

688687680 is an abundant number, since it is smaller than the sum of its proper divisors (1749468480).

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

688687680 is a wasteful number, since it uses less digits than its factorization.

688687680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2277 (or 2267 counting only the distinct ones).

The product of its (nonzero) digits is 6193152, while the sum is 57.

The square root of 688687680 is about 26242.8596002798. The cubic root of 688687680 is about 883.0950246742.

The spelling of 688687680 in words is "six hundred eighty-eight million, six hundred eighty-seven thousand, six hundred eighty".