205680239 has 2 divisors, whose sum is σ = 205680240. Its totient is φ = 205680238.

The previous prime is 205680217. The next prime is 205680253. The reversal of 205680239 is 932086502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 205680239 - 2²⁰ = 204631663 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 205680199 and 205680208.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205680289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102840119 + 102840120.

It is an arithmetic number, because the mean of its divisors is an integer number (102840120).

Almost surely, 2^205680239 is an apocalyptic number.

205680239 is a deficient number, since it is larger than the sum of its proper divisors (1).

205680239 is an equidigital number, since it uses as much as digits as its factorization.

205680239 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 205680239 is about 14341.5563660295. The cubic root of 205680239 is about 590.2883192947.

The spelling of 205680239 in words is "two hundred five million, six hundred eighty thousand, two hundred thirty-nine".