21222212121212 has 48 divisors (see below), whose sum is σ = 37284546496512. Its totient is φ = 10569586708800.

The previous prime is 21222212121197. The next prime is 21222212121223. The reversal of 21222212121212 is 21212121222212.

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

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 2886979337 + ... + 2886986687.

It is an arithmetic number, because the mean of its divisors is an integer number (776761385344).

Almost surely, 2^{21222212121212} is an apocalyptic number.

It is an amenable number.

21222212121212 is a deficient number, since it is larger than the sum of its proper divisors (16062334375300).

21222212121212 is a wasteful number, since it uses less digits than its factorization.

21222212121212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10458 (or 10456 counting only the distinct ones).

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

Adding to 21222212121212 its reverse (21212121222212), we get a palindrome (42434333343424).

The spelling of 21222212121212 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twelve".