2212212222221 has 4 divisors (see below), whose sum is σ = 2212459876092. Its totient is φ = 2211964568352.

The previous prime is 2212212222173. The next prime is 2212212222247. The reversal of 2212212222221 is 1222222122122.

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 1080531144196 + 1131681078025 = 1039486^2 + 1063805^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2212212222221 is a prime.

It is a super-2 number, since 2×2212212222221² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2212272222221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123813536 + ... + 123831401.

It is an arithmetic number, because the mean of its divisors is an integer number (553114969023).

Almost surely, 2^{2212212222221} is an apocalyptic number.

It is an amenable number.

2212212222221 is a deficient number, since it is larger than the sum of its proper divisors (247653871).

2212212222221 is an equidigital number, since it uses as much as digits as its factorization.

2212212222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247653870.

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

Adding to 2212212222221 its reverse (1222222122122), we get a palindrome (3434434344343).

It can be divided in two parts, 221221 and 2222221, that added together give a palindrome (2443442).

The spelling of 2212212222221 in words is "two trillion, two hundred twelve billion, two hundred twelve million, two hundred twenty-two thousand, two hundred twenty-one".