686137 has 4 divisors (see below), whose sum is σ = 726516. Its totient is φ = 645760.

The previous prime is 686131. The next prime is 686141. The reversal of 686137 is 731686.

686137 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 609961 + 76176 = 781^2 + 276^2 .

It is a cyclic number.

It is not a de Polignac number, because 686137 - 2⁷ = 686009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 686099 and 686108.

It is not an unprimeable number, because it can be changed into a prime (686131) 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, 20164 + ... + 20197.

It is an arithmetic number, because the mean of its divisors is an integer number (181629).

2⁶⁸⁶¹³⁷ is an apocalyptic number.

It is an amenable number.

686137 is a deficient number, since it is larger than the sum of its proper divisors (40379).

686137 is a wasteful number, since it uses less digits than its factorization.

686137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40378.

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

The square root of 686137 is about 828.3338698858. Note that the first 3 decimals coincide. The cubic root of 686137 is about 88.2003441625.

It can be divided in two parts, 68 and 6137, that multiplied together give a square (417316 = 646²).

The spelling of 686137 in words is "six hundred eighty-six thousand, one hundred thirty-seven".