688608720 has 60 divisors (see below), whose sum is σ = 2312580036. Its totient is φ = 183628800.

The previous prime is 688608719. The next prime is 688608721. The reversal of 688608720 is 27806886.

It is an interprime number because it is at equal distance from previous prime (688608719) and next prime (688608721).

It can be written as a sum of positive squares in 2 ways, for example, as 505710144 + 182898576 = 22488^2 + 13524^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688608721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 477481 + ... + 478920.

Almost surely, 2^688608720 is an apocalyptic number.

688608720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

688608720 is an abundant number, since it is smaller than the sum of its proper divisors (1623971316).

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

688608720 is a wasteful number, since it uses less digits than its factorization.

688608720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 956420 (or 956411 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The square root of 688608720 is about 26241.3551479340. The cubic root of 688608720 is about 883.0612735994.

The spelling of 688608720 in words is "six hundred eighty-eight million, six hundred eight thousand, seven hundred twenty".