231905 has 4 divisors (see below), whose sum is σ = 278292. Its totient is φ = 185520.

The previous prime is 231901. The next prime is 231919. The reversal of 231905 is 509132.

231905 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 118336 + 113569 = 344^2 + 337^2 .

It is not a de Polignac number, because 231905 - 2² = 231901 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231901) 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, 23186 + ... + 23195.

It is an arithmetic number, because the mean of its divisors is an integer number (69573).

2²³¹⁹⁰⁵ is an apocalyptic number.

It is an amenable number.

231905 is a deficient number, since it is larger than the sum of its proper divisors (46387).

231905 is an equidigital number, since it uses as much as digits as its factorization.

231905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46386.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 231905 is about 481.5651565469. The cubic root of 231905 is about 61.4379482969.

The spelling of 231905 in words is "two hundred thirty-one thousand, nine hundred five".