205813081 has 2 divisors, whose sum is σ = 205813082. Its totient is φ = 205813080.

The previous prime is 205813021. The next prime is 205813099. The reversal of 205813081 is 180318502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 189337600 + 16475481 = 13760^2 + 4059^2 .

It is a cyclic number.

It is not a de Polignac number, because 205813081 - 2⁹ = 205812569 is a prime.

It is a super-2 number, since 2×205813081² = 84718048621425122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (205813021) 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, 102906540 + 102906541.

It is an arithmetic number, because the mean of its divisors is an integer number (102906541).

Almost surely, 2^205813081 is an apocalyptic number.

It is an amenable number.

205813081 is a deficient number, since it is larger than the sum of its proper divisors (1).

205813081 is an equidigital number, since it uses as much as digits as its factorization.

205813081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 205813081 is about 14346.1869847008. The cubic root of 205813081 is about 590.4153744515.

The spelling of 205813081 in words is "two hundred five million, eight hundred thirteen thousand, eighty-one".