2211221221 has 8 divisors (see below), whose sum is σ = 2412590688. Its totient is φ = 2009910000.

The previous prime is 2211221209. The next prime is 2211221249. The reversal of 2211221221 is 1221221122.

It is a happy number.

2211221221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 2211221221 - 2¹⁷ = 2211090149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2211221195 and 2211221204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2211221251) 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, 114946 + ... + 132796.

It is an arithmetic number, because the mean of its divisors is an integer number (301573836).

Almost surely, 2^2211221221 is an apocalyptic number.

It is an amenable number.

2211221221 is a deficient number, since it is larger than the sum of its proper divisors (201369467).

2211221221 is a wasteful number, since it uses less digits than its factorization.

2211221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29123.

The product of its digits is 64, while the sum is 16.

The square root of 2211221221 is about 47023.6240734378. The cubic root of 2211221221 is about 1302.7989440101.

Adding to 2211221221 its reverse (1221221122), we get a palindrome (3432442343).

Subtracting from 2211221221 its reverse (1221221122), we obtain a palindrome (990000099).

It can be divided in two parts, 221122 and 1221, that multiplied together give a palindrome (269989962).

The spelling of 2211221221 in words is "two billion, two hundred eleven million, two hundred twenty-one thousand, two hundred twenty-one".