561636217 has 2 divisors, whose sum is σ = 561636218. Its totient is φ = 561636216.

The previous prime is 561636161. The next prime is 561636227. The reversal of 561636217 is 712636165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 509450041 + 52186176 = 22571^2 + 7224^2 .

It is a cyclic number.

It is not a de Polignac number, because 561636217 - 2¹¹ = 561634169 is a prime.

It is not a weakly prime, because it can be changed into another prime (561636227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280818108 + 280818109.

It is an arithmetic number, because the mean of its divisors is an integer number (280818109).

Almost surely, 2^561636217 is an apocalyptic number.

It is an amenable number.

561636217 is a deficient number, since it is larger than the sum of its proper divisors (1).

561636217 is an equidigital number, since it uses as much as digits as its factorization.

561636217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 37.

The square root of 561636217 is about 23698.8653103899. The cubic root of 561636217 is about 825.0590552155.

The spelling of 561636217 in words is "five hundred sixty-one million, six hundred thirty-six thousand, two hundred seventeen".