561868165 has 4 divisors (see below), whose sum is σ = 674241804. Its totient is φ = 449494528.

The previous prime is 561868147. The next prime is 561868169.

561868165 is nontrivially palindromic in base 10.

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 215238241 + 346629924 = 14671^2 + 18618^2 .

It is a cyclic number.

It is not a de Polignac number, because 561868165 - 2¹⁷ = 561737093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (561868169) 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, 56186812 + ... + 56186821.

It is an arithmetic number, because the mean of its divisors is an integer number (168560451).

Almost surely, 2^561868165 is an apocalyptic number.

It is an amenable number.

561868165 is a deficient number, since it is larger than the sum of its proper divisors (112373639).

561868165 is a wasteful number, since it uses less digits than its factorization.

561868165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112373638.

The product of its digits is 345600, while the sum is 46.

The square root of 561868165 is about 23703.7584572574. The cubic root of 561868165 is about 825.1726189148.

The spelling of 561868165 in words is "five hundred sixty-one million, eight hundred sixty-eight thousand, one hundred sixty-five".