688011680 has 96 divisors (see below), whose sum is σ = 1666299600. Its totient is φ = 268369920.

The previous prime is 688011659. The next prime is 688011683. The reversal of 688011680 is 86110886.

It can be written as a sum of positive squares in 8 ways, for example, as 86192656 + 601819024 = 9284^2 + 24532^2 .

It is not an unprimeable number, because it can be changed into a prime (688011683) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1532096 + ... + 1532544.

Almost surely, 2^688011680 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688011680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (833149800).

688011680 is an abundant number, since it is smaller than the sum of its proper divisors (978287920).

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

688011680 is a wasteful number, since it uses less digits than its factorization.

688011680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 682 (or 674 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 38.

The square root of 688011680 is about 26229.9767441757. The cubic root of 688011680 is about 882.8059881557.

The spelling of 688011680 in words is "six hundred eighty-eight million, eleven thousand, six hundred eighty".