243043399 has 2 divisors, whose sum is σ = 243043400. Its totient is φ = 243043398.

The previous prime is 243043397. The next prime is 243043429. The reversal of 243043399 is 993340342.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 243043399 - 2¹ = 243043397 is a prime.

Together with 243043397, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (243043391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121521699 + 121521700.

It is an arithmetic number, because the mean of its divisors is an integer number (121521700).

Almost surely, 2^243043399 is an apocalyptic number.

243043399 is a deficient number, since it is larger than the sum of its proper divisors (1).

243043399 is an equidigital number, since it uses as much as digits as its factorization.

243043399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69984, while the sum is 37.

The square root of 243043399 is about 15589.8492295468. The cubic root of 243043399 is about 624.0622943165.

The spelling of 243043399 in words is "two hundred forty-three million, forty-three thousand, three hundred ninety-nine".