21212011212 has 36 divisors (see below), whose sum is σ = 57575460600. Its totient is φ = 6060574464.

The previous prime is 21212011187. The next prime is 21212011243. The reversal of 21212011212 is 21211021212.

It is a junction number, because it is equal to n+sod(n) for n = 21212011191 and 21212011200.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18036837 + ... + 18038012.

It is an arithmetic number, because the mean of its divisors is an integer number (1599318350).

Almost surely, 2^21212011212 is an apocalyptic number.

It is an amenable number.

21212011212 is an abundant number, since it is smaller than the sum of its proper divisors (36363449388).

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

21212011212 is a wasteful number, since it uses less digits than its factorization.

21212011212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36074870 (or 36074861 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21212011212 its reverse (21211021212), we get a palindrome (42423032424).

The spelling of 21212011212 in words is "twenty-one billion, two hundred twelve million, eleven thousand, two hundred twelve".