686799 has 20 divisors (see below), whose sum is σ = 1050280. Its totient is φ = 447120.

The previous prime is 686797. The next prime is 686801. The reversal of 686799 is 997686.

It is an interprime number because it is at equal distance from previous prime (686797) and next prime (686801).

It is not a de Polignac number, because 686799 - 2¹ = 686797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686797) 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 19 ways as a sum of consecutive naturals, for example, 4872 + ... + 5010.

It is an arithmetic number, because the mean of its divisors is an integer number (52514).

2⁶⁸⁶⁷⁹⁹ is an apocalyptic number.

686799 is a deficient number, since it is larger than the sum of its proper divisors (363481).

686799 is a wasteful number, since it uses less digits than its factorization.

686799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212 (or 203 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 686799 is about 828.7333708739. The cubic root of 686799 is about 88.2287009191.

It can be divided in two parts, 686 and 799, that added together give a triangular number (1485 = T₅₄).

The spelling of 686799 in words is "six hundred eighty-six thousand, seven hundred ninety-nine".