205430243 has 2 divisors, whose sum is σ = 205430244. Its totient is φ = 205430242.

The previous prime is 205430237. The next prime is 205430297. The reversal of 205430243 is 342034502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205430243 - 2¹⁶ = 205364707 is a prime.

It is not a weakly prime, because it can be changed into another prime (205430543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102715121 + 102715122.

It is an arithmetic number, because the mean of its divisors is an integer number (102715122).

Almost surely, 2^205430243 is an apocalyptic number.

205430243 is a deficient number, since it is larger than the sum of its proper divisors (1).

205430243 is an equidigital number, since it uses as much as digits as its factorization.

205430243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 23.

The square root of 205430243 is about 14332.8379255471. The cubic root of 205430243 is about 590.0490651525.

Adding to 205430243 its reverse (342034502), we get a palindrome (547464745).

The spelling of 205430243 in words is "two hundred five million, four hundred thirty thousand, two hundred forty-three".