21212112212 has 12 divisors (see below), whose sum is σ = 37343480160. Its totient is φ = 10542546456.

The previous prime is 21212112209. The next prime is 21212112401. The reversal of 21212112212 is 21221121212.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15876662 + ... + 15877997.

It is an arithmetic number, because the mean of its divisors is an integer number (3111956680).

Almost surely, 2^21212112212 is an apocalyptic number.

It is an amenable number.

21212112212 is a deficient number, since it is larger than the sum of its proper divisors (16131367948).

21212112212 is a wasteful number, since it uses less digits than its factorization.

21212112212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31754830 (or 31754828 counting only the distinct ones).

The product of its digits is 64, while the sum is 17.

Adding to 21212112212 its reverse (21221121212), we get a palindrome (42433233424).

The spelling of 21212112212 in words is "twenty-one billion, two hundred twelve million, one hundred twelve thousand, two hundred twelve".