209428073 has 2 divisors, whose sum is σ = 209428074. Its totient is φ = 209428072.

The previous prime is 209428039. The next prime is 209428129. The reversal of 209428073 is 370824902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 188018944 + 21409129 = 13712^2 + 4627^2 .

It is a cyclic number.

It is not a de Polignac number, because 209428073 - 2¹⁴ = 209411689 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (209428273) 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, 104714036 + 104714037.

It is an arithmetic number, because the mean of its divisors is an integer number (104714037).

Almost surely, 2^209428073 is an apocalyptic number.

It is an amenable number.

209428073 is a deficient number, since it is larger than the sum of its proper divisors (1).

209428073 is an equidigital number, since it uses as much as digits as its factorization.

209428073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 209428073 is about 14471.6299358434. The cubic root of 209428073 is about 593.8521031723.

The spelling of 209428073 in words is "two hundred nine million, four hundred twenty-eight thousand, seventy-three".