686199 has 4 divisors (see below), whose sum is σ = 914936. Its totient is φ = 457464.

The previous prime is 686197. The next prime is 686201. The reversal of 686199 is 991686.

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

It is an interprime number because it is at equal distance from previous prime (686197) and next prime (686201).

It is not a de Polignac number, because 686199 - 2¹ = 686197 is a prime.

It is a D-number.

It is a Duffinian number.

686199 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686197) 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, 114364 + ... + 114369.

It is an arithmetic number, because the mean of its divisors is an integer number (228734).

2⁶⁸⁶¹⁹⁹ is an apocalyptic number.

686199 is a deficient number, since it is larger than the sum of its proper divisors (228737).

686199 is a wasteful number, since it uses less digits than its factorization.

686199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228736.

The product of its digits is 23328, while the sum is 39.

The square root of 686199 is about 828.3712935635. The cubic root of 686199 is about 88.2030007052.

The spelling of 686199 in words is "six hundred eighty-six thousand, one hundred ninety-nine".