243051221321 has 2 divisors, whose sum is σ = 243051221322. Its totient is φ = 243051221320.

The previous prime is 243051221263. The next prime is 243051221341. The reversal of 243051221321 is 123122150342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129643923721 + 113407297600 = 360061^2 + 336760^2 .

It is a cyclic number.

It is not a de Polignac number, because 243051221321 - 2¹⁰ = 243051220297 is a prime.

It is not a weakly prime, because it can be changed into another prime (243051221341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121525610660 + 121525610661.

It is an arithmetic number, because the mean of its divisors is an integer number (121525610661).

Almost surely, 2^243051221321 is an apocalyptic number.

It is an amenable number.

243051221321 is a deficient number, since it is larger than the sum of its proper divisors (1).

243051221321 is an equidigital number, since it uses as much as digits as its factorization.

243051221321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 26.

Adding to 243051221321 its reverse (123122150342), we get a palindrome (366173371663).

The spelling of 243051221321 in words is "two hundred forty-three billion, fifty-one million, two hundred twenty-one thousand, three hundred twenty-one".