231531263 has 4 divisors (see below), whose sum is σ = 232869768. Its totient is φ = 230192760.

The previous prime is 231531247. The next prime is 231531269. The reversal of 231531263 is 362135132.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 231531263 - 2⁴ = 231531247 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231531269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 668993 + ... + 669338.

It is an arithmetic number, because the mean of its divisors is an integer number (58217442).

Almost surely, 2^231531263 is an apocalyptic number.

231531263 is a deficient number, since it is larger than the sum of its proper divisors (1338505).

231531263 is a wasteful number, since it uses less digits than its factorization.

231531263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1338504.

The product of its digits is 3240, while the sum is 26.

The square root of 231531263 is about 15216.1513859451. The cubic root of 231531263 is about 614.0492618223.

Adding to 231531263 its reverse (362135132), we get a palindrome (593666395).

The spelling of 231531263 in words is "two hundred thirty-one million, five hundred thirty-one thousand, two hundred sixty-three".