2211221 has 4 divisors (see below), whose sum is σ = 2287500. Its totient is φ = 2134944.

The previous prime is 2211217. The next prime is 2211227. The reversal of 2211221 is 1221122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1240996 + 970225 = 1114^2 + 985^2 .

It is a cyclic number.

It is not a de Polignac number, because 2211221 - 2² = 2211217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2211227) 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, 38096 + ... + 38153.

It is an arithmetic number, because the mean of its divisors is an integer number (571875).

2^2211221 is an apocalyptic number.

It is an amenable number.

2211221 is a deficient number, since it is larger than the sum of its proper divisors (76279).

2211221 is an equidigital number, since it uses as much as digits as its factorization.

2211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76278.

The product of its digits is 16, while the sum is 11.

The square root of 2211221 is about 1487.0174847661. The cubic root of 2211221 is about 130.2798900607.

Adding to 2211221 its reverse (1221122), we get a palindrome (3432343).

Subtracting from 2211221 its reverse (1221122), we obtain a palindrome (990099).

The spelling of 2211221 in words is "two million, two hundred eleven thousand, two hundred twenty-one".