205191871 has 2 divisors, whose sum is σ = 205191872. Its totient is φ = 205191870.

The previous prime is 205191827. The next prime is 205191893. The reversal of 205191871 is 178191502.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 205191871 - 2⁹ = 205191359 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205191971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102595935 + 102595936.

It is an arithmetic number, because the mean of its divisors is an integer number (102595936).

Almost surely, 2^205191871 is an apocalyptic number.

205191871 is a deficient number, since it is larger than the sum of its proper divisors (1).

205191871 is an equidigital number, since it uses as much as digits as its factorization.

205191871 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5040, while the sum is 34.

The square root of 205191871 is about 14324.5199221475. The cubic root of 205191871 is about 589.8207547043.

The spelling of 205191871 in words is "two hundred five million, one hundred ninety-one thousand, eight hundred seventy-one".