231009 has 4 divisors (see below), whose sum is σ = 308016. Its totient is φ = 154004.

The previous prime is 231001. The next prime is 231017. The reversal of 231009 is 900132.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (231001) and next prime (231017).

It is a cyclic number.

It is not a de Polignac number, because 231009 - 2³ = 231001 is a prime.

It is an Ulam number.

It is a D-number.

231009 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (231001) 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, 38499 + ... + 38504.

It is an arithmetic number, because the mean of its divisors is an integer number (77004).

2²³¹⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

231009 is a deficient number, since it is larger than the sum of its proper divisors (77007).

231009 is an equidigital number, since it uses as much as digits as its factorization.

231009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77006.

The product of its (nonzero) digits is 54, while the sum is 15.

The square root of 231009 is about 480.6339563535. The cubic root of 231009 is about 61.3587212424.

The spelling of 231009 in words is "two hundred thirty-one thousand, nine".