561557755217 has 2 divisors, whose sum is σ = 561557755218. Its totient is φ = 561557755216.

The previous prime is 561557755163. The next prime is 561557755267. The reversal of 561557755217 is 712557755165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 558832497601 + 2725257616 = 747551^2 + 52204^2 .

It is a cyclic number.

It is not a de Polignac number, because 561557755217 - 2³⁶ = 492838278481 is a prime.

It is a super-2 number, since 2×561557755217² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (561557755267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280778877608 + 280778877609.

It is an arithmetic number, because the mean of its divisors is an integer number (280778877609).

Almost surely, 2^561557755217 is an apocalyptic number.

It is an amenable number.

561557755217 is a deficient number, since it is larger than the sum of its proper divisors (1).

561557755217 is an equidigital number, since it uses as much as digits as its factorization.

561557755217 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12862500, while the sum is 56.

The spelling of 561557755217 in words is "five hundred sixty-one billion, five hundred fifty-seven million, seven hundred fifty-five thousand, two hundred seventeen".