2221222221221 has 4 divisors (see below), whose sum is σ = 2221229380812. Its totient is φ = 2221215061632.

The previous prime is 2221222221191. The next prime is 2221222221233. The reversal of 2221222221221 is 1221222221222.

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 316422000196 + 1904800221025 = 562514^2 + 1380145^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221222221221 - 2¹⁴ = 2221222204837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2221222221821) 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, 3092300 + ... + 3742293.

It is an arithmetic number, because the mean of its divisors is an integer number (555307345203).

Almost surely, 2^{2221222221221} is an apocalyptic number.

It is an amenable number.

2221222221221 is a deficient number, since it is larger than the sum of its proper divisors (7159591).

2221222221221 is an equidigital number, since it uses as much as digits as its factorization.

2221222221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7159590.

The product of its digits is 1024, while the sum is 23.

Adding to 2221222221221 its reverse (1221222221222), we get a palindrome (3442444442443).

Subtracting from 2221222221221 its reverse (1221222221222), we obtain a palindrome (999999999999).

The spelling of 2221222221221 in words is "two trillion, two hundred twenty-one billion, two hundred twenty-two million, two hundred twenty-one thousand, two hundred twenty-one".