2211221212221 has 32 divisors (see below), whose sum is σ = 3570602508288. Its totient is φ = 1188255594240.

The previous prime is 2211221212183. The next prime is 2211221212237. The reversal of 2211221212221 is 1222121221122.

It is not a de Polignac number, because 2211221212221 - 2⁶ = 2211221212157 is a prime.

It is a super-2 number, since 2×2211221212221² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2211221214221) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2095645 + ... + 2968866.

It is an arithmetic number, because the mean of its divisors is an integer number (111581328384).

Almost surely, 2^{2211221212221} is an apocalyptic number.

2211221212221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

2211221212221 is a deficient number, since it is larger than the sum of its proper divisors (1359381296067).

2211221212221 is a wasteful number, since it uses less digits than its factorization.

2211221212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5065761.

The product of its digits is 256, while the sum is 21.

Adding to 2211221212221 its reverse (1222121221122), we get a palindrome (3433342433343).

The spelling of 2211221212221 in words is "two trillion, two hundred eleven billion, two hundred twenty-one million, two hundred twelve thousand, two hundred twenty-one".