243400321 has 2 divisors, whose sum is σ = 243400322. Its totient is φ = 243400320.

The previous prime is 243400307. The next prime is 243400349. The reversal of 243400321 is 123004342.

243400321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 238270096 + 5130225 = 15436^2 + 2265^2 .

It is a cyclic number.

It is not a de Polignac number, because 243400321 - 2⁹ = 243399809 is a prime.

It is not a weakly prime, because it can be changed into another prime (243400301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121700160 + 121700161.

It is an arithmetic number, because the mean of its divisors is an integer number (121700161).

Almost surely, 2^243400321 is an apocalyptic number.

It is an amenable number.

243400321 is a deficient number, since it is larger than the sum of its proper divisors (1).

243400321 is an equidigital number, since it uses as much as digits as its factorization.

243400321 is an evil number, because the sum of its binary digits is even.

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

The square root of 243400321 is about 15601.2922862178. The cubic root of 243400321 is about 624.3676343176.

Adding to 243400321 its reverse (123004342), we get a palindrome (366404663).

The spelling of 243400321 in words is "two hundred forty-three million, four hundred thousand, three hundred twenty-one".