205680281 has 2 divisors, whose sum is σ = 205680282. Its totient is φ = 205680280.

The previous prime is 205680253. The next prime is 205680287. The reversal of 205680281 is 182086502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 204490000 + 1190281 = 14300^2 + 1091^2 .

It is a cyclic number.

It is not a de Polignac number, because 205680281 - 2⁶ = 205680217 is a prime.

It is a super-2 number, since 2×205680281² = 84608755984477922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (205680287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102840140 + 102840141.

It is an arithmetic number, because the mean of its divisors is an integer number (102840141).

Almost surely, 2^205680281 is an apocalyptic number.

It is an amenable number.

205680281 is a deficient number, since it is larger than the sum of its proper divisors (1).

205680281 is an equidigital number, since it uses as much as digits as its factorization.

205680281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 205680281 is about 14341.5578303056. The cubic root of 205680281 is about 590.2883594737.

The spelling of 205680281 in words is "two hundred five million, six hundred eighty thousand, two hundred eighty-one".