21222222101221 has 8 divisors (see below), whose sum is σ = 22339224112320. Its totient is φ = 20105224385472.

The previous prime is 21222222101209. The next prime is 21222222101251. The reversal of 21222222101221 is 12210122222212.

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 21222222101221 - 2⁵ = 21222222101189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21222222101192 and 21222222101201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222222101251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16158381 + ... + 17422333.

It is an arithmetic number, because the mean of its divisors is an integer number (2792403014040).

Almost surely, 2^{21222222101221} is an apocalyptic number.

It is an amenable number.

21222222101221 is a deficient number, since it is larger than the sum of its proper divisors (1117002011099).

21222222101221 is a wasteful number, since it uses less digits than its factorization.

21222222101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2147675.

The product of its (nonzero) digits is 512, while the sum is 22.

Adding to 21222222101221 its reverse (12210122222212), we get a palindrome (33432344323433).

The spelling of 21222222101221 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred twenty-two million, one hundred one thousand, two hundred twenty-one".