561287688217 has 2 divisors, whose sum is σ = 561287688218. Its totient is φ = 561287688216.

The previous prime is 561287688083. The next prime is 561287688287. The reversal of 561287688217 is 712886782165.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 560086095321 + 1201592896 = 748389^2 + 34664^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561287688217 is a prime.

It is not a weakly prime, because it can be changed into another prime (561287688287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280643844108 + 280643844109.

It is an arithmetic number, because the mean of its divisors is an integer number (280643844109).

Almost surely, 2^561287688217 is an apocalyptic number.

It is an amenable number.

561287688217 is a deficient number, since it is larger than the sum of its proper divisors (1).

561287688217 is an equidigital number, since it uses as much as digits as its factorization.

561287688217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18063360, while the sum is 61.

The spelling of 561287688217 in words is "five hundred sixty-one billion, two hundred eighty-seven million, six hundred eighty-eight thousand, two hundred seventeen".