20565550289 has 2 divisors, whose sum is σ = 20565550290. Its totient is φ = 20565550288.

The previous prime is 20565550193. The next prime is 20565550307. The reversal of 20565550289 is 98205556502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20223115264 + 342435025 = 142208^2 + 18505^2 .

It is a cyclic number.

It is not a de Polignac number, because 20565550289 - 2¹² = 20565546193 is a prime.

It is not a weakly prime, because it can be changed into another prime (20565550589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10282775144 + 10282775145.

It is an arithmetic number, because the mean of its divisors is an integer number (10282775145).

Almost surely, 2^20565550289 is an apocalyptic number.

It is an amenable number.

20565550289 is a deficient number, since it is larger than the sum of its proper divisors (1).

20565550289 is an equidigital number, since it uses as much as digits as its factorization.

20565550289 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080000, while the sum is 47.

The spelling of 20565550289 in words is "twenty billion, five hundred sixty-five million, five hundred fifty thousand, two hundred eighty-nine".