243311201321 has 2 divisors, whose sum is σ = 243311201322. Its totient is φ = 243311201320.

The previous prime is 243311201311. The next prime is 243311201323. The reversal of 243311201321 is 123102113342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 163329139600 + 79982061721 = 404140^2 + 282811^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243311201321 is a prime.

Together with 243311201323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (243311201323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121655600660 + 121655600661.

It is an arithmetic number, because the mean of its divisors is an integer number (121655600661).

Almost surely, 2^243311201321 is an apocalyptic number.

It is an amenable number.

243311201321 is a deficient number, since it is larger than the sum of its proper divisors (1).

243311201321 is an equidigital number, since it uses as much as digits as its factorization.

243311201321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 243311201321 its reverse (123102113342), we get a palindrome (366413314663).

The spelling of 243311201321 in words is "two hundred forty-three billion, three hundred eleven million, two hundred one thousand, three hundred twenty-one".