243120131321 has 2 divisors, whose sum is σ = 243120131322. Its totient is φ = 243120131320.

The previous prime is 243120131299. The next prime is 243120131323. The reversal of 243120131321 is 123131021342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 218804095225 + 24316036096 = 467765^2 + 155936^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-243120131321 is a prime.

Together with 243120131323, 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 (243120131323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121560065660 + 121560065661.

It is an arithmetic number, because the mean of its divisors is an integer number (121560065661).

Almost surely, 2^243120131321 is an apocalyptic number.

It is an amenable number.

243120131321 is a deficient number, since it is larger than the sum of its proper divisors (1).

243120131321 is an equidigital number, since it uses as much as digits as its factorization.

243120131321 is an odious number, because the sum of its binary digits is odd.

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

Adding to 243120131321 its reverse (123131021342), we get a palindrome (366251152663).

The spelling of 243120131321 in words is "two hundred forty-three billion, one hundred twenty million, one hundred thirty-one thousand, three hundred twenty-one".