2809221 has 4 divisors (see below), whose sum is σ = 3745632. Its totient is φ = 1872812.

The previous prime is 2809211. The next prime is 2809223. The reversal of 2809221 is 1229082.

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 2809221 - 2¹⁷ = 2678149 is a prime.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 2809191 and 2809200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2809223) 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, 468201 + ... + 468206.

It is an arithmetic number, because the mean of its divisors is an integer number (936408).

2^2809221 is an apocalyptic number.

It is an amenable number.

2809221 is a deficient number, since it is larger than the sum of its proper divisors (936411).

2809221 is an equidigital number, since it uses as much as digits as its factorization.

2809221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936410.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 2809221 is about 1676.0730890984. The cubic root of 2809221 is about 141.1005268731.

The spelling of 2809221 in words is "two million, eight hundred nine thousand, two hundred twenty-one".