2191209 has 8 divisors (see below), whose sum is σ = 2940192. Its totient is φ = 1451520.

The previous prime is 2191199. The next prime is 2191229. The reversal of 2191209 is 9021912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2191209 - 2⁴ = 2191193 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2191229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1752 + ... + 2729.

It is an arithmetic number, because the mean of its divisors is an integer number (367524).

2^2191209 is an apocalyptic number.

It is an amenable number.

2191209 is a deficient number, since it is larger than the sum of its proper divisors (748983).

2191209 is a wasteful number, since it uses less digits than its factorization.

2191209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4647.

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 2191209 is about 1480.2732855794. The cubic root of 2191209 is about 129.8856785884.

The spelling of 2191209 in words is "two million, one hundred ninety-one thousand, two hundred nine".