231523561 has 8 divisors (see below), whose sum is σ = 246934440. Its totient is φ = 216311808.

The previous prime is 231523547. The next prime is 231523571. The reversal of 231523561 is 165325132.

It can be written as a sum of positive squares in 4 ways, for example, as 88003161 + 143520400 = 9381^2 + 11980^2 .

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

It is not a de Polignac number, because 231523561 - 2¹¹ = 231521513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231523511) 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, 47376 + ... + 52033.

It is an arithmetic number, because the mean of its divisors is an integer number (30866805).

Almost surely, 2^231523561 is an apocalyptic number.

It is an amenable number.

231523561 is a deficient number, since it is larger than the sum of its proper divisors (15410879).

231523561 is a wasteful number, since it uses less digits than its factorization.

231523561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99563.

The product of its digits is 5400, while the sum is 28.

The square root of 231523561 is about 15215.8982975045. The cubic root of 231523561 is about 614.0424528644.

Adding to 231523561 its reverse (165325132), we get a palindrome (396848693).

The spelling of 231523561 in words is "two hundred thirty-one million, five hundred twenty-three thousand, five hundred sixty-one".