561505165 has 16 divisors (see below), whose sum is σ = 728482608. Its totient is φ = 413024256.

The previous prime is 561505151. The next prime is 561505199.

561505165 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 8 ways, for example, as 3175524 + 558329641 = 1782^2 + 23629^2 .

It is a cyclic number.

It is not a de Polignac number, because 561505165 - 2⁷ = 561505037 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 561505165.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 102 + ... + 33511.

It is an arithmetic number, because the mean of its divisors is an integer number (45530163).

Almost surely, 2^561505165 is an apocalyptic number.

It is an amenable number.

561505165 is a deficient number, since it is larger than the sum of its proper divisors (166977443).

561505165 is a wasteful number, since it uses less digits than its factorization.

561505165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33888.

The product of its (nonzero) digits is 22500, while the sum is 34.

The square root of 561505165 is about 23696.1002065741. The cubic root of 561505165 is about 824.9948772256.

The spelling of 561505165 in words is "five hundred sixty-one million, five hundred five thousand, one hundred sixty-five".