205986191 has 2 divisors, whose sum is σ = 205986192. Its totient is φ = 205986190.

The previous prime is 205986181. The next prime is 205986223. The reversal of 205986191 is 191689502.

It is a happy number.

205986191 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205986191 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205986181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102993095 + 102993096.

It is an arithmetic number, because the mean of its divisors is an integer number (102993096).

Almost surely, 2^205986191 is an apocalyptic number.

205986191 is a deficient number, since it is larger than the sum of its proper divisors (1).

205986191 is an equidigital number, since it uses as much as digits as its factorization.

205986191 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 41.

The square root of 205986191 is about 14352.2190270355. The cubic root of 205986191 is about 590.5808614440.

The spelling of 205986191 in words is "two hundred five million, nine hundred eighty-six thousand, one hundred ninety-one".