688561458 has 16 divisors (see below), whose sum is σ = 1483055616. Its totient is φ = 211865040.

The previous prime is 688561441. The next prime is 688561459. The reversal of 688561458 is 854165886.

It is a happy number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 688561458.

It is not an unprimeable number, because it can be changed into a prime (688561459) 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 7 ways as a sum of consecutive naturals, for example, 4413778 + ... + 4413933.

It is an arithmetic number, because the mean of its divisors is an integer number (92690976).

Almost surely, 2^688561458 is an apocalyptic number.

688561458 is an abundant number, since it is smaller than the sum of its proper divisors (794494158).

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

688561458 is a wasteful number, since it uses less digits than its factorization.

688561458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8827729.

The product of its digits is 1843200, while the sum is 51.

The square root of 688561458 is about 26240.4546073425. The cubic root of 688561458 is about 883.0410704489.

The spelling of 688561458 in words is "six hundred eighty-eight million, five hundred sixty-one thousand, four hundred fifty-eight".