688091879450 has 24 divisors (see below), whose sum is σ = 1303999030908. Its totient is φ = 270043604480.

The previous prime is 688091879429. The next prime is 688091879479. The reversal of 688091879450 is 54978190886.

It can be written as a sum of positive squares in 6 ways, for example, as 543114463369 + 144977416081 = 736963^2 + 380759^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 129826007 + ... + 129831306.

Almost surely, 2^688091879450 is an apocalyptic number.

688091879450 is a deficient number, since it is larger than the sum of its proper divisors (615907151458).

688091879450 is a wasteful number, since it uses less digits than its factorization.

688091879450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259657378 (or 259657373 counting only the distinct ones).

The product of its (nonzero) digits is 34836480, while the sum is 65.

The spelling of 688091879450 in words is "six hundred eighty-eight billion, ninety-one million, eight hundred seventy-nine thousand, four hundred fifty".