205168505 has 4 divisors (see below), whose sum is σ = 246202212. Its totient is φ = 164134800.

The previous prime is 205168493. The next prime is 205168507. The reversal of 205168505 is 505861502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 505861502 = 2 ⋅252930751.

It can be written as a sum of positive squares in 2 ways, for example, as 152053561 + 53114944 = 12331^2 + 7288^2 .

It is not a de Polignac number, because 205168505 - 2¹⁶ = 205102969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205168507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20516846 + ... + 20516855.

It is an arithmetic number, because the mean of its divisors is an integer number (61550553).

Almost surely, 2^205168505 is an apocalyptic number.

It is an amenable number.

205168505 is a deficient number, since it is larger than the sum of its proper divisors (41033707).

205168505 is an equidigital number, since it uses as much as digits as its factorization.

205168505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41033706.

The product of its (nonzero) digits is 12000, while the sum is 32.

The square root of 205168505 is about 14323.7043044039. The cubic root of 205168505 is about 589.7983654565.

The spelling of 205168505 in words is "two hundred five million, one hundred sixty-eight thousand, five hundred five".