205656050606561 has 2 divisors, whose sum is σ = 205656050606562. Its totient is φ = 205656050606560.

The previous prime is 205656050606551. The next prime is 205656050606593. The reversal of 205656050606561 is 165606050656502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 201181742661025 + 4474307945536 = 14183855^2 + 2115256^2 .

It is a cyclic number.

It is not a de Polignac number, because 205656050606561 - 2⁶ = 205656050606497 is a prime.

It is a super-2 number, since 2×205656050606561² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (205656050606551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102828025303280 + 102828025303281.

It is an arithmetic number, because the mean of its divisors is an integer number (102828025303281).

Almost surely, 2^{205656050606561} is an apocalyptic number.

It is an amenable number.

205656050606561 is a deficient number, since it is larger than the sum of its proper divisors (1).

205656050606561 is an equidigital number, since it uses as much as digits as its factorization.

205656050606561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720000, while the sum is 53.

The spelling of 205656050606561 in words is "two hundred five trillion, six hundred fifty-six billion, fifty million, six hundred six thousand, five hundred sixty-one".