685131 has 16 divisors (see below), whose sum is σ = 967680. Its totient is φ = 430560.

The previous prime is 685123. The next prime is 685141. The reversal of 685131 is 131586.

685131 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 685131 - 2³ = 685123 is a prime.

It is a super-2 number, since 2×685131² = 938808974322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (685141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4860 + ... + 4998.

It is an arithmetic number, because the mean of its divisors is an integer number (60480).

2⁶⁸⁵¹³¹ is an apocalyptic number.

685131 is the 524-th centered pentagonal number.

685131 is a deficient number, since it is larger than the sum of its proper divisors (282549).

685131 is a wasteful number, since it uses less digits than its factorization.

685131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226.

The product of its digits is 720, while the sum is 24.

The square root of 685131 is about 827.7264040732. The cubic root of 685131 is about 88.1572172330.

The spelling of 685131 in words is "six hundred eighty-five thousand, one hundred thirty-one".