686559 has 4 divisors (see below), whose sum is σ = 915416. Its totient is φ = 457704.

The previous prime is 686551. The next prime is 686563. The reversal of 686559 is 955686.

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

It is not a de Polignac number, because 686559 - 2³ = 686551 is a prime.

It is a D-number.

It is a Duffinian number.

686559 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 686559.

It is not an unprimeable number, because it can be changed into a prime (686551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114424 + ... + 114429.

It is an arithmetic number, because the mean of its divisors is an integer number (228854).

2⁶⁸⁶⁵⁵⁹ is an apocalyptic number.

686559 is a deficient number, since it is larger than the sum of its proper divisors (228857).

686559 is a wasteful number, since it uses less digits than its factorization.

686559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228856.

The product of its digits is 64800, while the sum is 39.

The square root of 686559 is about 828.5885589362. The cubic root of 686559 is about 88.2184226304.

The spelling of 686559 in words is "six hundred eighty-six thousand, five hundred fifty-nine".