561646165 has 8 divisors (see below), whose sum is σ = 674128728. Its totient is φ = 449214720.

The previous prime is 561646147. The next prime is 561646229.

561646165 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 63776196 + 497869969 = 7986^2 + 22313^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 561646165 - 2¹⁹ = 561121877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18249 + ... + 38161.

It is an arithmetic number, because the mean of its divisors is an integer number (84266091).

Almost surely, 2^561646165 is an apocalyptic number.

It is an amenable number.

561646165 is a deficient number, since it is larger than the sum of its proper divisors (112482563).

561646165 is a wasteful number, since it uses less digits than its factorization.

561646165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25559.

The product of its digits is 129600, while the sum is 40.

The square root of 561646165 is about 23699.0751929268. The cubic root of 561646165 is about 825.0639264820.

The spelling of 561646165 in words is "five hundred sixty-one million, six hundred forty-six thousand, one hundred sixty-five".