21222111222212 has 18 divisors (see below), whose sum is σ = 38022471052398. Its totient is φ = 10364286872352.

The previous prime is 21222111222211. The next prime is 21222111222217. The reversal of 21222111222212 is 21222211122212.

It can be written as a sum of positive squares in only one way, i.e., 20853050112196 + 369061110016 = 4566514^2 + 607504^2 .

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21222111222211) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1434694553 + ... + 1434709344.

It is an arithmetic number, because the mean of its divisors is an integer number (2112359502911).

Almost surely, 2^{21222111222212} is an apocalyptic number.

It is an amenable number.

21222111222212 is a deficient number, since it is larger than the sum of its proper divisors (16800359830186).

21222111222212 is a wasteful number, since it uses less digits than its factorization.

21222111222212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2869403987 (or 2869403942 counting only the distinct ones).

The product of its digits is 512, while the sum is 23.

Adding to 21222111222212 its reverse (21222211122212), we get a palindrome (42444322344424).

The spelling of 21222111222212 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred eleven million, two hundred twenty-two thousand, two hundred twelve".