18200209 has 2 divisors, whose sum is σ = 18200210. Its totient is φ = 18200208.

The previous prime is 18200191. The next prime is 18200213. The reversal of 18200209 is 90200281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12780625 + 5419584 = 3575^2 + 2328^2 .

It is an emirp because it is prime and its reverse (90200281) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18200209 - 2⁵ = 18200177 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18200209.

It is not a weakly prime, because it can be changed into another prime (18200219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9100104 + 9100105.

It is an arithmetic number, because the mean of its divisors is an integer number (9100105).

Almost surely, 2^18200209 is an apocalyptic number.

It is an amenable number.

18200209 is a deficient number, since it is larger than the sum of its proper divisors (1).

18200209 is an equidigital number, since it uses as much as digits as its factorization.

18200209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 18200209 is about 4266.1702966478. The cubic root of 18200209 is about 263.0422183041.

The spelling of 18200209 in words is "eighteen million, two hundred thousand, two hundred nine".