205129549 has 2 divisors, whose sum is σ = 205129550. Its totient is φ = 205129548.

The previous prime is 205129523. The next prime is 205129553. The reversal of 205129549 is 945921502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 200420649 + 4708900 = 14157^2 + 2170^2 .

It is a cyclic number.

It is not a de Polignac number, because 205129549 - 2⁹ = 205129037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205129559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102564774 + 102564775.

It is an arithmetic number, because the mean of its divisors is an integer number (102564775).

Almost surely, 2^205129549 is an apocalyptic number.

It is an amenable number.

205129549 is a deficient number, since it is larger than the sum of its proper divisors (1).

205129549 is an equidigital number, since it uses as much as digits as its factorization.

205129549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32400, while the sum is 37.

The square root of 205129549 is about 14322.3443960826. The cubic root of 205129549 is about 589.7610341265.

The spelling of 205129549 in words is "two hundred five million, one hundred twenty-nine thousand, five hundred forty-nine".