5561255561 has 2 divisors, whose sum is σ = 5561255562. Its totient is φ = 5561255560.

The previous prime is 5561255551. The next prime is 5561255617. The reversal of 5561255561 is 1655521655.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2817486400 + 2743769161 = 53080^2 + 52381^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5561255561 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (5561255501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2780627780 + 2780627781.

It is an arithmetic number, because the mean of its divisors is an integer number (2780627781).

Almost surely, 2^5561255561 is an apocalyptic number.

It is an amenable number.

5561255561 is a deficient number, since it is larger than the sum of its proper divisors (1).

5561255561 is an equidigital number, since it uses as much as digits as its factorization.

5561255561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 225000, while the sum is 41.

The square root of 5561255561 is about 74573.8262462105. The cubic root of 5561255561 is about 1771.7031242303.

The spelling of 5561255561 in words is "five billion, five hundred sixty-one million, two hundred fifty-five thousand, five hundred sixty-one".