205088030809 has 2 divisors, whose sum is σ = 205088030810. Its totient is φ = 205088030808.

The previous prime is 205088030789. The next prime is 205088030867. The reversal of 205088030809 is 908030880502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 159942405184 + 45145625625 = 399928^2 + 212475^2 .

It is a cyclic number.

It is not a de Polignac number, because 205088030809 - 2¹³ = 205088022617 is a prime.

It is a super-2 number, since 2×205088030809² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (205088030009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102544015404 + 102544015405.

It is an arithmetic number, because the mean of its divisors is an integer number (102544015405).

Almost surely, 2^205088030809 is an apocalyptic number.

It is an amenable number.

205088030809 is a deficient number, since it is larger than the sum of its proper divisors (1).

205088030809 is an equidigital number, since it uses as much as digits as its factorization.

205088030809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 138240, while the sum is 43.

The spelling of 205088030809 in words is "two hundred five billion, eighty-eight million, thirty thousand, eight hundred nine".