561651161 has 2 divisors, whose sum is σ = 561651162. Its totient is φ = 561651160.

The previous prime is 561651133. The next prime is 561651163. The reversal of 561651161 is 161156165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 374809600 + 186841561 = 19360^2 + 13669^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561651161 is a prime.

Together with 561651163, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (561651163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280825580 + 280825581.

It is an arithmetic number, because the mean of its divisors is an integer number (280825581).

Almost surely, 2^561651161 is an apocalyptic number.

It is an amenable number.

561651161 is a deficient number, since it is larger than the sum of its proper divisors (1).

561651161 is an equidigital number, since it uses as much as digits as its factorization.

561651161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5400, while the sum is 32.

The square root of 561651161 is about 23699.1805976494. The cubic root of 561651161 is about 825.0663728663.

The spelling of 561651161 in words is "five hundred sixty-one million, six hundred fifty-one thousand, one hundred sixty-one".