561155665717 has 2 divisors, whose sum is σ = 561155665718. Its totient is φ = 561155665716.

The previous prime is 561155665633. The next prime is 561155665727. The reversal of 561155665717 is 717566551165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 559490536081 + 1665129636 = 747991^2 + 40806^2 .

It is a cyclic number.

It is not a de Polignac number, because 561155665717 - 2¹⁵ = 561155632949 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561155665727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280577832858 + 280577832859.

It is an arithmetic number, because the mean of its divisors is an integer number (280577832859).

Almost surely, 2^561155665717 is an apocalyptic number.

It is an amenable number.

561155665717 is a deficient number, since it is larger than the sum of its proper divisors (1).

561155665717 is an equidigital number, since it uses as much as digits as its factorization.

561155665717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6615000, while the sum is 55.

The spelling of 561155665717 in words is "five hundred sixty-one billion, one hundred fifty-five million, six hundred sixty-five thousand, seven hundred seventeen".