205515502341161 has 2 divisors, whose sum is σ = 205515502341162. Its totient is φ = 205515502341160.

The previous prime is 205515502341151. The next prime is 205515502341209. The reversal of 205515502341161 is 161143205515502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 205490246774761 + 25255566400 = 14334931^2 + 158920^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205515502341161 is a prime.

It is not a weakly prime, because it can be changed into another prime (205515502341101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102757751170580 + 102757751170581.

It is an arithmetic number, because the mean of its divisors is an integer number (102757751170581).

Almost surely, 2^{205515502341161} is an apocalyptic number.

It is an amenable number.

205515502341161 is a deficient number, since it is larger than the sum of its proper divisors (1).

205515502341161 is an equidigital number, since it uses as much as digits as its factorization.

205515502341161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 180000, while the sum is 41.

Adding to 205515502341161 its reverse (161143205515502), we get a palindrome (366658707856663).

The spelling of 205515502341161 in words is "two hundred five trillion, five hundred fifteen billion, five hundred two million, three hundred forty-one thousand, one hundred sixty-one".