688591 has 2 divisors, whose sum is σ = 688592. Its totient is φ = 688590.

The previous prime is 688573. The next prime is 688621. The reversal of 688591 is 195886.

688591 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 688591 - 2¹³ = 680399 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 688591.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344295 + 344296.

It is an arithmetic number, because the mean of its divisors is an integer number (344296).

2⁶⁸⁸⁵⁹¹ is an apocalyptic number.

688591 is a deficient number, since it is larger than the sum of its proper divisors (1).

688591 is an equidigital number, since it uses as much as digits as its factorization.

688591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 37.

The square root of 688591 is about 829.8138345436. The cubic root of 688591 is about 88.3053698916.

The spelling of 688591 in words is "six hundred eighty-eight thousand, five hundred ninety-one".