686149 has 2 divisors, whose sum is σ = 686150. Its totient is φ = 686148.

The previous prime is 686143. The next prime is 686173. The reversal of 686149 is 941686.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 540225 + 145924 = 735^2 + 382^2 .

It is a cyclic number.

It is not a de Polignac number, because 686149 - 2³ = 686141 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (686141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343074 + 343075.

It is an arithmetic number, because the mean of its divisors is an integer number (343075).

2⁶⁸⁶¹⁴⁹ is an apocalyptic number.

It is an amenable number.

686149 is a deficient number, since it is larger than the sum of its proper divisors (1).

686149 is an equidigital number, since it uses as much as digits as its factorization.

686149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 34.

The square root of 686149 is about 828.3411133102. The cubic root of 686149 is about 88.2008583446.

The spelling of 686149 in words is "six hundred eighty-six thousand, one hundred forty-nine".