205744321 has 2 divisors, whose sum is σ = 205744322. Its totient is φ = 205744320.

The previous prime is 205744313. The next prime is 205744397. The reversal of 205744321 is 123447502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 183982096 + 21762225 = 13564^2 + 4665^2 .

It is a cyclic number.

It is not a de Polignac number, because 205744321 - 2³ = 205744313 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205744321.

It is not a weakly prime, because it can be changed into another prime (205744621) 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, 102872160 + 102872161.

It is an arithmetic number, because the mean of its divisors is an integer number (102872161).

Almost surely, 2^205744321 is an apocalyptic number.

It is an amenable number.

205744321 is a deficient number, since it is larger than the sum of its proper divisors (1).

205744321 is an equidigital number, since it uses as much as digits as its factorization.

205744321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 28.

The square root of 205744321 is about 14343.7903289193. The cubic root of 205744321 is about 590.3496165920.

The spelling of 205744321 in words is "two hundred five million, seven hundred forty-four thousand, three hundred twenty-one".