205139287 has 2 divisors, whose sum is σ = 205139288. Its totient is φ = 205139286.

The previous prime is 205139269. The next prime is 205139299. The reversal of 205139287 is 782931502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 205139287 - 2⁷ = 205139159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205139227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102569643 + 102569644.

It is an arithmetic number, because the mean of its divisors is an integer number (102569644).

Almost surely, 2^205139287 is an apocalyptic number.

205139287 is a deficient number, since it is larger than the sum of its proper divisors (1).

205139287 is an equidigital number, since it uses as much as digits as its factorization.

205139287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 205139287 is about 14322.6843503584. The cubic root of 205139287 is about 589.7703664438.

The spelling of 205139287 in words is "two hundred five million, one hundred thirty-nine thousand, two hundred eighty-seven".