205800993 has 20 divisors (see below), whose sum is σ = 315744660. Its totient is φ = 133490592.

The previous prime is 205800983. The next prime is 205801009. The reversal of 205800993 is 399008502.

It can be written as a sum of positive squares in 2 ways, for example, as 198894609 + 6906384 = 14103^2 + 2628^2 .

It is not a de Polignac number, because 205800993 - 2¹⁰ = 205799969 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (205800953) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 31338 + ... + 37331.

It is an arithmetic number, because the mean of its divisors is an integer number (15787233).

Almost surely, 2^205800993 is an apocalyptic number.

It is an amenable number.

205800993 is a deficient number, since it is larger than the sum of its proper divisors (109943667).

205800993 is an equidigital number, since it uses as much as digits as its factorization.

205800993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68718 (or 68709 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 205800993 is about 14345.7656819007. The cubic root of 205800993 is about 590.4038152887.

The spelling of 205800993 in words is "two hundred five million, eight hundred thousand, nine hundred ninety-three".