231505 has 4 divisors (see below), whose sum is σ = 277812. Its totient is φ = 185200.

The previous prime is 231503. The next prime is 231529. The reversal of 231505 is 505132.

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 77841 + 153664 = 279^2 + 392^2 .

It is not a de Polignac number, because 231505 - 2¹ = 231503 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23146 + ... + 23155.

It is an arithmetic number, because the mean of its divisors is an integer number (69453).

2²³¹⁵⁰⁵ is an apocalyptic number.

It is an amenable number.

231505 is a deficient number, since it is larger than the sum of its proper divisors (46307).

231505 is an equidigital number, since it uses as much as digits as its factorization.

231505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46306.

The product of its (nonzero) digits is 150, while the sum is 16.

The square root of 231505 is about 481.1496648653. The cubic root of 231505 is about 61.4026043380.

Adding to 231505 its reverse (505132), we get a palindrome (736637).

The spelling of 231505 in words is "two hundred thirty-one thousand, five hundred five".