205368409 has 2 divisors, whose sum is σ = 205368410. Its totient is φ = 205368408.

The previous prime is 205368367. The next prime is 205368419. The reversal of 205368409 is 904863502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115498009 + 89870400 = 10747^2 + 9480^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205368409 is a prime.

It is not a weakly prime, because it can be changed into another prime (205368419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102684204 + 102684205.

It is an arithmetic number, because the mean of its divisors is an integer number (102684205).

Almost surely, 2^205368409 is an apocalyptic number.

It is an amenable number.

205368409 is a deficient number, since it is larger than the sum of its proper divisors (1).

205368409 is an equidigital number, since it uses as much as digits as its factorization.

205368409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 205368409 is about 14330.6806886484. The cubic root of 205368409 is about 589.9898581039.

The spelling of 205368409 in words is "two hundred five million, three hundred sixty-eight thousand, four hundred nine".