205949831 has 2 divisors, whose sum is σ = 205949832. Its totient is φ = 205949830.

The previous prime is 205949803. The next prime is 205949837. The reversal of 205949831 is 138949502.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-205949831 is a prime.

It is a super-2 number, since 2×205949831² = 84830665777857122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205949837) 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, 102974915 + 102974916.

It is an arithmetic number, because the mean of its divisors is an integer number (102974916).

Almost surely, 2^205949831 is an apocalyptic number.

205949831 is a deficient number, since it is larger than the sum of its proper divisors (1).

205949831 is an equidigital number, since it uses as much as digits as its factorization.

205949831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 77760, while the sum is 41.

The square root of 205949831 is about 14350.9522680552. The cubic root of 205949831 is about 590.5461102735.

The spelling of 205949831 in words is "two hundred five million, nine hundred forty-nine thousand, eight hundred thirty-one".