209068813 has 2 divisors, whose sum is σ = 209068814. Its totient is φ = 209068812.

The previous prime is 209068789. The next prime is 209068819. The reversal of 209068813 is 318860902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 170093764 + 38975049 = 13042^2 + 6243^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209068813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209068819) 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, 104534406 + 104534407.

It is an arithmetic number, because the mean of its divisors is an integer number (104534407).

Almost surely, 2^209068813 is an apocalyptic number.

It is an amenable number.

209068813 is a deficient number, since it is larger than the sum of its proper divisors (1).

209068813 is an equidigital number, since it uses as much as digits as its factorization.

209068813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 209068813 is about 14459.2120463046. The cubic root of 209068813 is about 593.5123374884.

The spelling of 209068813 in words is "two hundred nine million, sixty-eight thousand, eight hundred thirteen".