688690081728 has 840 divisors, whose sum is σ = 2345052390912. Its totient is φ = 199469952000.

The previous prime is 688690081699. The next prime is 688690081741. The reversal of 688690081728 is 827180096886.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 2080634523 + ... + 2080634853.

Almost surely, 2^688690081728 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 688690081728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1172526195456).

688690081728 is an abundant number, since it is smaller than the sum of its proper divisors (1656362309184).

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

688690081728 is a wasteful number, since it uses less digits than its factorization.

688690081728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 515 (or 485 counting only the distinct ones).

The product of its (nonzero) digits is 18579456, while the sum is 63.

The spelling of 688690081728 in words is "six hundred eighty-eight billion, six hundred ninety million, eighty-one thousand, seven hundred twenty-eight".