686131 has 2 divisors, whose sum is σ = 686132. Its totient is φ = 686130.

The previous prime is 686117. The next prime is 686141. The reversal of 686131 is 131686.

686131 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 686131 - 2⁵ = 686099 is a prime.

It is a super-2 number, since 2×686131² = 941551498322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 686096 and 686105.

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, 343065 + 343066.

It is an arithmetic number, because the mean of its divisors is an integer number (343066).

2⁶⁸⁶¹³¹ is an apocalyptic number.

686131 is a deficient number, since it is larger than the sum of its proper divisors (1).

686131 is an equidigital number, since it uses as much as digits as its factorization.

686131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 25.

The square root of 686131 is about 828.3302481499. The cubic root of 686131 is about 88.2000870693.

The spelling of 686131 in words is "six hundred eighty-six thousand, one hundred thirty-one".