565661161 has 4 divisors (see below), whose sum is σ = 609173572. Its totient is φ = 522148752.

The previous prime is 565661099. The next prime is 565661167. The reversal of 565661161 is 161166565.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 28302400 + 537358761 = 5320^2 + 23181^2 .

It is a cyclic number.

It is not a de Polignac number, because 565661161 - 2⁹ = 565660649 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 565661161.

It is not an unprimeable number, because it can be changed into a prime (565661167) 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, 21756186 + ... + 21756211.

It is an arithmetic number, because the mean of its divisors is an integer number (152293393).

Almost surely, 2^565661161 is an apocalyptic number.

It is an amenable number.

565661161 is a deficient number, since it is larger than the sum of its proper divisors (43512411).

565661161 is a wasteful number, since it uses less digits than its factorization.

565661161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43512410.

The product of its digits is 32400, while the sum is 37.

The square root of 565661161 is about 23783.6322078862. The cubic root of 565661161 is about 827.0252835280.

The spelling of 565661161 in words is "five hundred sixty-five million, six hundred sixty-one thousand, one hundred sixty-one".