231565 has 8 divisors (see below), whose sum is σ = 287640. Its totient is φ = 178752.

The previous prime is 231563. The next prime is 231571. The reversal of 231565 is 565132.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 6889 + 224676 = 83^2 + 474^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 231565 - 2¹ = 231563 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 654 + ... + 943.

It is an arithmetic number, because the mean of its divisors is an integer number (35955).

2²³¹⁵⁶⁵ is an apocalyptic number.

It is an amenable number.

231565 is a deficient number, since it is larger than the sum of its proper divisors (56075).

231565 is a wasteful number, since it uses less digits than its factorization.

231565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1631.

The product of its digits is 900, while the sum is 22.

The square root of 231565 is about 481.2120114877. The cubic root of 231565 is about 61.4079085259.

Adding to 231565 its reverse (565132), we get a palindrome (796697).

The spelling of 231565 in words is "two hundred thirty-one thousand, five hundred sixty-five".