211009 has 4 divisors (see below), whose sum is σ = 213760. Its totient is φ = 208260.

The previous prime is 211007. The next prime is 211039. The reversal of 211009 is 900112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 211009 - 2¹ = 211007 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 211009.

It is not an unprimeable number, because it can be changed into a prime (211007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1257 + ... + 1414.

It is an arithmetic number, because the mean of its divisors is an integer number (53440).

2²¹¹⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

211009 is a deficient number, since it is larger than the sum of its proper divisors (2751).

211009 is an equidigital number, since it uses as much as digits as its factorization.

211009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2750.

The product of its (nonzero) digits is 18, while the sum is 13.

The square root of 211009 is about 459.3571595175. The cubic root of 211009 is about 59.5342645661.

It can be divided in two parts, 2 and 11009, that added together give a palindrome (11011).

The spelling of 211009 in words is "two hundred eleven thousand, nine".