231539 has 16 divisors (see below), whose sum is σ = 301056. Its totient is φ = 172800.

The previous prime is 231533. The next prime is 231547. The reversal of 231539 is 935132.

It is a happy number.

231539 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231539 is a prime.

It is a super-2 number, since 2×231539² = 107220617042, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (231533) 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, 2339 + ... + 2435.

It is an arithmetic number, because the mean of its divisors is an integer number (18816).

2²³¹⁵³⁹ is an apocalyptic number.

231539 is a deficient number, since it is larger than the sum of its proper divisors (69517).

231539 is a wasteful number, since it uses less digits than its factorization.

231539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146.

The product of its digits is 810, while the sum is 23.

The square root of 231539 is about 481.1849956098. The cubic root of 231539 is about 61.4056101570.

The spelling of 231539 in words is "two hundred thirty-one thousand, five hundred thirty-nine".