688541605 has 8 divisors (see below), whose sum is σ = 826400664. Its totient is φ = 550732800.

The previous prime is 688541591. The next prime is 688541629. The reversal of 688541605 is 506145886.

It can be written as a sum of positive squares in 4 ways, for example, as 146676321 + 541865284 = 12111^2 + 23278^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 688541605 - 2⁵ = 688541573 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31885 + ... + 48925.

It is an arithmetic number, because the mean of its divisors is an integer number (103300083).

Almost surely, 2^688541605 is an apocalyptic number.

It is an amenable number.

688541605 is a deficient number, since it is larger than the sum of its proper divisors (137859059).

688541605 is a wasteful number, since it uses less digits than its factorization.

688541605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25127.

The product of its (nonzero) digits is 230400, while the sum is 43.

The square root of 688541605 is about 26240.0763146756. The cubic root of 688541605 is about 883.0325835846.

The spelling of 688541605 in words is "six hundred eighty-eight million, five hundred forty-one thousand, six hundred five".