205565601 has 16 divisors (see below), whose sum is σ = 286473600. Its totient is φ = 130948608.

The previous prime is 205565587. The next prime is 205565609. The reversal of 205565601 is 106565502.

It is not a de Polignac number, because 205565601 - 2⁹ = 205565089 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205565609) 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 15 ways as a sum of consecutive naturals, for example, 3741 + ... + 20618.

It is an arithmetic number, because the mean of its divisors is an integer number (17904600).

Almost surely, 2^205565601 is an apocalyptic number.

It is an amenable number.

205565601 is a deficient number, since it is larger than the sum of its proper divisors (80907999).

205565601 is a wasteful number, since it uses less digits than its factorization.

205565601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24488.

The product of its (nonzero) digits is 9000, while the sum is 30.

The square root of 205565601 is about 14337.5591018834. The cubic root of 205565601 is about 590.1786311550.

Subtracting from 205565601 its reverse (106565502), we obtain a palindrome (99000099).

The spelling of 205565601 in words is "two hundred five million, five hundred sixty-five thousand, six hundred one".