205135565 has 4 divisors (see below), whose sum is σ = 246162684. Its totient is φ = 164108448.

The previous prime is 205135517. The next prime is 205135577. The reversal of 205135565 is 565531502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 565531502 = 2 ⋅282765751.

It can be written as a sum of positive squares in 2 ways, for example, as 110229001 + 94906564 = 10499^2 + 9742^2 .

It is a cyclic number.

It is not a de Polignac number, because 205135565 - 2¹⁰ = 205134541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20513552 + ... + 20513561.

It is an arithmetic number, because the mean of its divisors is an integer number (61540671).

Almost surely, 2^205135565 is an apocalyptic number.

It is an amenable number.

205135565 is a deficient number, since it is larger than the sum of its proper divisors (41027119).

205135565 is an equidigital number, since it uses as much as digits as its factorization.

205135565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41027118.

The product of its (nonzero) digits is 22500, while the sum is 32.

The square root of 205135565 is about 14322.5544160251. The cubic root of 205135565 is about 589.7667995363.

The spelling of 205135565 in words is "two hundred five million, one hundred thirty-five thousand, five hundred sixty-five".