686173 has 2 divisors, whose sum is σ = 686174. Its totient is φ = 686172.

The previous prime is 686149. The next prime is 686177. The reversal of 686173 is 371686.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 558009 + 128164 = 747^2 + 358^2 .

It is a cyclic number.

It is not a de Polignac number, because 686173 - 2⁵ = 686141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (686177) 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 as a sum of consecutive naturals, namely, 343086 + 343087.

It is an arithmetic number, because the mean of its divisors is an integer number (343087).

2⁶⁸⁶¹⁷³ is an apocalyptic number.

It is an amenable number.

686173 is a deficient number, since it is larger than the sum of its proper divisors (1).

686173 is an equidigital number, since it uses as much as digits as its factorization.

686173 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6048, while the sum is 31.

The square root of 686173 is about 828.3555999690. The cubic root of 686173 is about 88.2018866907.

It can be divided in two parts, 68 and 6173, that added together give a square (6241 = 79²).

The spelling of 686173 in words is "six hundred eighty-six thousand, one hundred seventy-three".