231709 has 2 divisors, whose sum is σ = 231710. Its totient is φ = 231708.

The previous prime is 231701. The next prime is 231719. The reversal of 231709 is 907132.

231709 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 225625 + 6084 = 475^2 + 78^2 .

It is a cyclic number.

It is not a de Polignac number, because 231709 - 2³ = 231701 is a prime.

It is a Chen prime.

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 231709.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115854 + 115855.

It is an arithmetic number, because the mean of its divisors is an integer number (115855).

2²³¹⁷⁰⁹ is an apocalyptic number.

It is an amenable number.

231709 is a deficient number, since it is larger than the sum of its proper divisors (1).

231709 is an equidigital number, since it uses as much as digits as its factorization.

231709 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 378, while the sum is 22.

The square root of 231709 is about 481.3616104344. The cubic root of 231709 is about 61.4206348396.

The spelling of 231709 in words is "two hundred thirty-one thousand, seven hundred nine".