205021513 has 6 divisors (see below), whose sum is σ = 217791326. Its totient is φ = 192961152.

The previous prime is 205021489. The next prime is 205021529. The reversal of 205021513 is 315120502.

It can be written as a sum of positive squares in 3 ways, for example, as 101042704 + 103978809 = 10052^2 + 10197^2 .

It is not a de Polignac number, because 205021513 - 2¹³ = 205013321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205021613) 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 in 5 ways as a sum of consecutive naturals, for example, 354420 + ... + 354997.

Almost surely, 2^205021513 is an apocalyptic number.

It is an amenable number.

205021513 is a deficient number, since it is larger than the sum of its proper divisors (12769813).

205021513 is an equidigital number, since it uses as much as digits as its factorization.

205021513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 709451 (or 709434 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 205021513 is about 14318.5723101153. The cubic root of 205021513 is about 589.6574790604.

The spelling of 205021513 in words is "two hundred five million, twenty-one thousand, five hundred thirteen".