205106813 has 2 divisors, whose sum is σ = 205106814. Its totient is φ = 205106812.

The previous prime is 205106779. The next prime is 205106857. The reversal of 205106813 is 318601502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 196504324 + 8602489 = 14018^2 + 2933^2 .

It is a cyclic number.

It is not a de Polignac number, because 205106813 - 2²⁴ = 188329597 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205102813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102553406 + 102553407.

It is an arithmetic number, because the mean of its divisors is an integer number (102553407).

Almost surely, 2^205106813 is an apocalyptic number.

It is an amenable number.

205106813 is a deficient number, since it is larger than the sum of its proper divisors (1).

205106813 is an equidigital number, since it uses as much as digits as its factorization.

205106813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 205106813 is about 14321.5506492838. The cubic root of 205106813 is about 589.7392441531.

The spelling of 205106813 in words is "two hundred five million, one hundred six thousand, eight hundred thirteen".