686885 has 8 divisors (see below), whose sum is σ = 872856. Its totient is φ = 517120.

The previous prime is 686879. The next prime is 686891. The reversal of 686885 is 588686.

It is an interprime number because it is at equal distance from previous prime (686879) and next prime (686891).

It can be written as a sum of positive squares in 4 ways, for example, as 98596 + 588289 = 314^2 + 767^2 .

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

It is not a de Polignac number, because 686885 - 2¹² = 682789 is a prime.

It is a super-2 number, since 2×686885² = 943622006450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3956 + ... + 4125.

It is an arithmetic number, because the mean of its divisors is an integer number (109107).

2⁶⁸⁶⁸⁸⁵ is an apocalyptic number.

It is an amenable number.

686885 is a deficient number, since it is larger than the sum of its proper divisors (185971).

686885 is a wasteful number, since it uses less digits than its factorization.

686885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8103.

The product of its digits is 92160, while the sum is 41.

The square root of 686885 is about 828.7852556604. The cubic root of 686885 is about 88.2323833898.

The spelling of 686885 in words is "six hundred eighty-six thousand, eight hundred eighty-five".