561641611 has 4 divisors (see below), whose sum is σ = 576821152. Its totient is φ = 546462072.

The previous prime is 561641581. The next prime is 561641617. The reversal of 561641611 is 116146165.

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

It is a cyclic number.

It is not a de Polignac number, because 561641611 - 2¹⁵ = 561608843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561641617) 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, 7589715 + ... + 7589788.

It is an arithmetic number, because the mean of its divisors is an integer number (144205288).

Almost surely, 2^561641611 is an apocalyptic number.

561641611 is a deficient number, since it is larger than the sum of its proper divisors (15179541).

561641611 is a wasteful number, since it uses less digits than its factorization.

561641611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15179540.

The product of its digits is 4320, while the sum is 31.

The square root of 561641611 is about 23698.9791130335. The cubic root of 561641611 is about 825.0616965185.

Adding to 561641611 its reverse (116146165), we get a palindrome (677787776).

It can be divided in two parts, 56164 and 1611, that added together give a palindrome (57775).

The spelling of 561641611 in words is "five hundred sixty-one million, six hundred forty-one thousand, six hundred eleven".