565166561 has 4 divisors (see below), whose sum is σ = 565410324. Its totient is φ = 564922800.

The previous prime is 565166551. The next prime is 565166597. The reversal of 565166561 is 165661565.

565166561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 165661565 = 5 ⋅33132313.

It can be written as a sum of positive squares in 2 ways, for example, as 348046336 + 217120225 = 18656^2 + 14735^2 .

It is a cyclic number.

It is not a de Polignac number, because 565166561 - 2²² = 560972257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (565166521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118370 + ... + 123051.

It is an arithmetic number, because the mean of its divisors is an integer number (141352581).

Almost surely, 2^565166561 is an apocalyptic number.

It is an amenable number.

565166561 is a deficient number, since it is larger than the sum of its proper divisors (243763).

565166561 is a wasteful number, since it uses less digits than its factorization.

565166561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243762.

The product of its digits is 162000, while the sum is 41.

The square root of 565166561 is about 23773.2320267985. The cubic root of 565166561 is about 826.7841698180.

The spelling of 565166561 in words is "five hundred sixty-five million, one hundred sixty-six thousand, five hundred sixty-one".