21212212212222 has 64 divisors (see below), whose sum is σ = 43783611105024. Its totient is φ = 6848917724160.

The previous prime is 21212212212211. The next prime is 21212212212239. The reversal of 21212212212222 is 22221221221212.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 21212212212192 and 21212212212201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3116772 + ... + 7220712.

It is an arithmetic number, because the mean of its divisors is an integer number (684118923516).

Almost surely, 2^{21212212212222} is an apocalyptic number.

21212212212222 is an abundant number, since it is smaller than the sum of its proper divisors (22571398892802).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21212212212222 is a wasteful number, since it uses less digits than its factorization.

21212212212222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4104233.

The product of its digits is 1024, while the sum is 24.

Adding to 21212212212222 its reverse (22221221221212), we get a palindrome (43433433433434).

The spelling of 21212212212222 in words is "twenty-one trillion, two hundred twelve billion, two hundred twelve million, two hundred twelve thousand, two hundred twenty-two".