243402409 has 2 divisors, whose sum is σ = 243402410. Its totient is φ = 243402408.

The previous prime is 243402373. The next prime is 243402433. The reversal of 243402409 is 904204342.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 197121600 + 46280809 = 14040^2 + 6803^2 .

It is a cyclic number.

It is not a de Polignac number, because 243402409 - 2¹¹ = 243400361 is a prime.

It is not a weakly prime, because it can be changed into another prime (243402449) 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, 121701204 + 121701205.

It is an arithmetic number, because the mean of its divisors is an integer number (121701205).

Almost surely, 2^243402409 is an apocalyptic number.

It is an amenable number.

243402409 is a deficient number, since it is larger than the sum of its proper divisors (1).

243402409 is an equidigital number, since it uses as much as digits as its factorization.

243402409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 243402409 is about 15601.3592036079. The cubic root of 243402409 is about 624.3694196835.

The spelling of 243402409 in words is "two hundred forty-three million, four hundred two thousand, four hundred nine".