243240520231 has 4 divisors (see below), whose sum is σ = 243245921832. Its totient is φ = 243235118632.

The previous prime is 243240520219. The next prime is 243240520267. The reversal of 243240520231 is 132025042342.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 132025042342 = 2 ⋅66012521171.

It is a cyclic number.

It is not a de Polignac number, because 243240520231 - 2¹⁵ = 243240487463 is a prime.

It is a super-2 number, since 2×243240520231² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 243240520231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (243240520531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2632681 + ... + 2723506.

It is an arithmetic number, because the mean of its divisors is an integer number (60811480458).

Almost surely, 2^243240520231 is an apocalyptic number.

243240520231 is a deficient number, since it is larger than the sum of its proper divisors (5401601).

243240520231 is an equidigital number, since it uses as much as digits as its factorization.

243240520231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5401600.

The product of its (nonzero) digits is 11520, while the sum is 28.

Adding to 243240520231 its reverse (132025042342), we get a palindrome (375265562573).

The spelling of 243240520231 in words is "two hundred forty-three billion, two hundred forty million, five hundred twenty thousand, two hundred thirty-one".