561116161 has 4 divisors (see below), whose sum is σ = 594123012. Its totient is φ = 528109312.

The previous prime is 561116147. The next prime is 561116177. The reversal of 561116161 is 161611165.

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 339701761 + 221414400 = 18431^2 + 14880^2 .

It is a cyclic number.

It is not a de Polignac number, because 561116161 - 2¹³ = 561107969 is a prime.

It is a super-2 number, since 2×561116161² = 629702692270755842, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561116261) 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, 16503400 + ... + 16503433.

It is an arithmetic number, because the mean of its divisors is an integer number (148530753).

Almost surely, 2^561116161 is an apocalyptic number.

It is an amenable number.

561116161 is a deficient number, since it is larger than the sum of its proper divisors (33006851).

561116161 is a wasteful number, since it uses less digits than its factorization.

561116161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33006850.

The product of its digits is 1080, while the sum is 28.

The square root of 561116161 is about 23687.8905983627. The cubic root of 561116161 is about 824.8043177158.

The spelling of 561116161 in words is "five hundred sixty-one million, one hundred sixteen thousand, one hundred sixty-one".