2811221 has 16 divisors (see below), whose sum is σ = 3532800. Its totient is φ = 2181168.

The previous prime is 2811217. The next prime is 2811227. The reversal of 2811221 is 1221182.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 2811221 - 2² = 2811217 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2811221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2811227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2600 + ... + 3518.

It is an arithmetic number, because the mean of its divisors is an integer number (220800).

2^2811221 is an apocalyptic number.

It is an amenable number.

2811221 is a deficient number, since it is larger than the sum of its proper divisors (721579).

2811221 is a wasteful number, since it uses less digits than its factorization.

2811221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 968.

The product of its digits is 64, while the sum is 17.

The square root of 2811221 is about 1676.6696156369. The cubic root of 2811221 is about 141.1340040198.

The spelling of 2811221 in words is "two million, eight hundred eleven thousand, two hundred twenty-one".