2001800209 has 2 divisors, whose sum is σ = 2001800210. Its totient is φ = 2001800208.

The previous prime is 2001800179. The next prime is 2001800257. The reversal of 2001800209 is 9020081002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1783203984 + 218596225 = 42228^2 + 14785^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001800209 - 2⁹ = 2001799697 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2001800209.

It is not a weakly prime, because it can be changed into another prime (2001800279) 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, 1000900104 + 1000900105.

It is an arithmetic number, because the mean of its divisors is an integer number (1000900105).

Almost surely, 2^2001800209 is an apocalyptic number.

It is an amenable number.

2001800209 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001800209 is an equidigital number, since it uses as much as digits as its factorization.

2001800209 is an odious number, because the sum of its binary digits is odd.

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

The square root of 2001800209 is about 44741.4819714323. The cubic root of 2001800209 is about 1260.2989567345.

The spelling of 2001800209 in words is "two billion, one million, eight hundred thousand, two hundred nine".