2109221 has 4 divisors (see below), whose sum is σ = 2136000. Its totient is φ = 2082444.

The previous prime is 2109203. The next prime is 2109223. The reversal of 2109221 is 1229012.

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 a de Polignac number, because none of the positive numbers 2^k-2109221 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 2109221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2109223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13271 + ... + 13428.

It is an arithmetic number, because the mean of its divisors is an integer number (534000).

2^2109221 is an apocalyptic number.

It is an amenable number.

2109221 is a deficient number, since it is larger than the sum of its proper divisors (26779).

2109221 is an equidigital number, since it uses as much as digits as its factorization.

2109221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26778.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 2109221 is about 1452.3157370214. The cubic root of 2109221 is about 128.2450749020.

The spelling of 2109221 in words is "two million, one hundred nine thousand, two hundred twenty-one".