561665426276917 has 2 divisors, whose sum is σ = 561665426276918. Its totient is φ = 561665426276916.

The previous prime is 561665426276891. The next prime is 561665426276953. The reversal of 561665426276917 is 719672624566165.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 293898872223441 + 267766554053476 = 17143479^2 + 16363574^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-561665426276917 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 561665426276917.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561665426270917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280832713138458 + 280832713138459.

It is an arithmetic number, because the mean of its divisors is an integer number (280832713138459).

Almost surely, 2^{561665426276917} is an apocalyptic number.

It is an amenable number.

561665426276917 is a deficient number, since it is larger than the sum of its proper divisors (1).

561665426276917 is an equidigital number, since it uses as much as digits as its factorization.

561665426276917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1371686400, while the sum is 73.

The spelling of 561665426276917 in words is "five hundred sixty-one trillion, six hundred sixty-five billion, four hundred twenty-six million, two hundred seventy-six thousand, nine hundred seventeen".