686171 has 8 divisors (see below), whose sum is σ = 733824. Its totient is φ = 639360.

The previous prime is 686149. The next prime is 686173. The reversal of 686171 is 171686.

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

It is a cyclic number.

It is not a de Polignac number, because 686171 - 2¹⁴ = 669787 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 7.

It is a zygodrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (686173) by changing a digit.

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, 2966 + ... + 3188.

It is an arithmetic number, because the mean of its divisors is an integer number (91728).

2⁶⁸⁶¹⁷¹ is an apocalyptic number.

686171 is a deficient number, since it is larger than the sum of its proper divisors (47653).

686171 is a wasteful number, since it uses less digits than its factorization.

686171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421.

The product of its digits is 2016, while the sum is 29.

The square root of 686171 is about 828.3543927571. The cubic root of 686171 is about 88.2018009961.

The spelling of 686171 in words is "six hundred eighty-six thousand, one hundred seventy-one".