2001209 has 6 divisors (see below), whose sum is σ = 2327994. Its totient is φ = 1715280.

The previous prime is 2001199. The next prime is 2001211. The reversal of 2001209 is 9021002.

It can be written as a sum of positive squares in only one way, i.e., 1960000 + 41209 = 1400^2 + 203^2 .

It is not a de Polignac number, because 2001209 - 2⁸ = 2000953 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001193 and 2001202.

It is not an unprimeable number, because it can be changed into a prime (2001229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 20372 + ... + 20469.

It is an arithmetic number, because the mean of its divisors is an integer number (387999).

2^2001209 is an apocalyptic number.

It is an amenable number.

2001209 is a deficient number, since it is larger than the sum of its proper divisors (326785).

2001209 is an equidigital number, since it uses as much as digits as its factorization.

2001209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40855 (or 40848 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 2001209 is about 1414.6409438441. The cubic root of 2001209 is about 126.0174872848.

The spelling of 2001209 in words is "two million, one thousand, two hundred nine".