688887385 has 4 divisors (see below), whose sum is σ = 826664868. Its totient is φ = 551109904.

The previous prime is 688887377. The next prime is 688887403. The reversal of 688887385 is 583788886.

688887385 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 493195264 + 195692121 = 22208^2 + 13989^2 .

It is a cyclic number.

It is not a de Polignac number, because 688887385 - 2³ = 688887377 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68888734 + ... + 68888743.

It is an arithmetic number, because the mean of its divisors is an integer number (206666217).

Almost surely, 2^688887385 is an apocalyptic number.

It is an amenable number.

688887385 is a deficient number, since it is larger than the sum of its proper divisors (137777483).

688887385 is a wasteful number, since it uses less digits than its factorization.

688887385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137777482.

The product of its digits is 20643840, while the sum is 61.

The square root of 688887385 is about 26246.6642642451. The cubic root of 688887385 is about 883.1803761104.

The spelling of 688887385 in words is "six hundred eighty-eight million, eight hundred eighty-seven thousand, three hundred eighty-five".