243040321 has 2 divisors, whose sum is σ = 243040322. Its totient is φ = 243040320.

The previous prime is 243040247. The next prime is 243040327. The reversal of 243040321 is 123040342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 187388721 + 55651600 = 13689^2 + 7460^2 .

It is a cyclic number.

It is not a de Polignac number, because 243040321 - 2¹⁵ = 243007553 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (243040327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121520160 + 121520161.

It is an arithmetic number, because the mean of its divisors is an integer number (121520161).

Almost surely, 2^243040321 is an apocalyptic number.

It is an amenable number.

243040321 is a deficient number, since it is larger than the sum of its proper divisors (1).

243040321 is an equidigital number, since it uses as much as digits as its factorization.

243040321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 243040321 is about 15589.7505111532. The cubic root of 243040321 is about 624.0596598462.

Adding to 243040321 its reverse (123040342), we get a palindrome (366080663).

The spelling of 243040321 in words is "two hundred forty-three million, forty thousand, three hundred twenty-one".