231309 has 16 divisors (see below), whose sum is σ = 369600. Its totient is φ = 142128.

The previous prime is 231299. The next prime is 231317. The reversal of 231309 is 903132.

It is not a de Polignac number, because 231309 - 2⁴ = 231293 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 231291 and 231300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231349) 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, 22 + ... + 680.

It is an arithmetic number, because the mean of its divisors is an integer number (23100).

2²³¹³⁰⁹ is an apocalyptic number.

It is an amenable number.

231309 is a deficient number, since it is larger than the sum of its proper divisors (138291).

231309 is a wasteful number, since it uses less digits than its factorization.

231309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681 (or 675 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 18.

The square root of 231309 is about 480.9459429083. The cubic root of 231309 is about 61.3852709350.

The spelling of 231309 in words is "two hundred thirty-one thousand, three hundred nine".