212211122222221 has 16 divisors (see below), whose sum is σ = 215879891724288. Its totient is φ = 208564124227200.

The previous prime is 212211122222219. The next prime is 212211122222249. The reversal of 212211122222221 is 122222221112212.

It is a cyclic number.

It is not a de Polignac number, because 212211122222221 - 2¹ = 212211122222219 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 (212211122222521) 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 15 ways as a sum of consecutive naturals, for example, 21723460 + ... + 29938786.

It is an arithmetic number, because the mean of its divisors is an integer number (13492493232768).

Almost surely, 2^{212211122222221} is an apocalyptic number.

It is an amenable number.

212211122222221 is a deficient number, since it is larger than the sum of its proper divisors (3668769502067).

212211122222221 is an equidigital number, since it uses as much as digits as its factorization.

212211122222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8216652.

The product of its digits is 1024, while the sum is 25.

Adding to 212211122222221 its reverse (122222221112212), we get a palindrome (334433343334433).

The spelling of 212211122222221 in words is "two hundred twelve trillion, two hundred eleven billion, one hundred twenty-two million, two hundred twenty-two thousand, two hundred twenty-one".