243123403321 has 4 divisors (see below), whose sum is σ = 243988611444. Its totient is φ = 242258195200.

The previous prime is 243123403307. The next prime is 243123403379. The reversal of 243123403321 is 123304321342.

It is a happy number.

243123403321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 209822628096 + 33300775225 = 458064^2 + 182485^2 .

It is a cyclic number.

It is not a de Polignac number, because 243123403321 - 2¹⁹ = 243122879033 is a prime.

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 243123403321.

It is not an unprimeable number, because it can be changed into a prime (243123400321) 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, 432603640 + ... + 432604201.

It is an arithmetic number, because the mean of its divisors is an integer number (60997152861).

Almost surely, 2^243123403321 is an apocalyptic number.

It is an amenable number.

243123403321 is a deficient number, since it is larger than the sum of its proper divisors (865208123).

243123403321 is an equidigital number, since it uses as much as digits as its factorization.

243123403321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 865208122.

The product of its (nonzero) digits is 10368, while the sum is 28.

Adding to 243123403321 its reverse (123304321342), we get a palindrome (366427724663).

The spelling of 243123403321 in words is "two hundred forty-three billion, one hundred twenty-three million, four hundred three thousand, three hundred twenty-one".