21121212222212 has 12 divisors (see below), whose sum is σ = 37568057805516. Its totient is φ = 10387481420640.

The previous prime is 21121212222181. The next prime is 21121212222247. The reversal of 21121212222212 is 21222221212112.

It can be written as a sum of positive squares in 2 ways, for example, as 3649681651396 + 17471530570816 = 1910414^2 + 4179896^2 .

It is a super-2 number, since 2×21121212222212² (a number of 27 digits) contains 22 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43281172343 + ... + 43281172830.

It is an arithmetic number, because the mean of its divisors is an integer number (3130671483793).

Almost surely, 2^{21121212222212} is an apocalyptic number.

It is an amenable number.

21121212222212 is a deficient number, since it is larger than the sum of its proper divisors (16446845583304).

21121212222212 is a wasteful number, since it uses less digits than its factorization.

21121212222212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86562345238 (or 86562345236 counting only the distinct ones).

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

Adding to 21121212222212 its reverse (21222221212112), we get a palindrome (42343433434324).

The spelling of 21121212222212 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twelve million, two hundred twenty-two thousand, two hundred twelve".