688628880 has 60 divisors (see below), whose sum is σ = 2312647740. Its totient is φ = 183634176.

The previous prime is 688628873. The next prime is 688628909. The reversal of 688628880 is 88826886.

688628880 is a `hidden beast` number, since 6 + 8 + 8 + 628 + 8 + 8 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 72795024 + 615833856 = 8532^2 + 24816^2 .

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

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 477495 + ... + 478934.

It is an arithmetic number, because the mean of its divisors is an integer number (38544129).

Almost surely, 2^688628880 is an apocalyptic number.

688628880 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

688628880 is an abundant number, since it is smaller than the sum of its proper divisors (1624018860).

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

688628880 is a wasteful number, since it uses less digits than its factorization.

688628880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 956448 (or 956439 counting only the distinct ones).

The product of its (nonzero) digits is 2359296, while the sum is 54.

The square root of 688628880 is about 26241.7392716260. The cubic root of 688628880 is about 883.0698911403.

The spelling of 688628880 in words is "six hundred eighty-eight million, six hundred twenty-eight thousand, eight hundred eighty".