21213311212 has 24 divisors (see below), whose sum is σ = 39322006416. Its totient is φ = 9978928128.

The previous prime is 21213311167. The next prime is 21213311221. The reversal of 21213311212 is 21211331212.

It is a self number, because there is not a number n which added to its sum of digits gives 21213311212.

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 7 ways as a sum of consecutive naturals, for example, 124308 + ... + 240580.

It is an arithmetic number, because the mean of its divisors is an integer number (1638416934).

Almost surely, 2^21213311212 is an apocalyptic number.

It is an amenable number.

21213311212 is a deficient number, since it is larger than the sum of its proper divisors (18108695204).

21213311212 is a wasteful number, since it uses less digits than its factorization.

21213311212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118977 (or 118975 counting only the distinct ones).

The product of its digits is 144, while the sum is 19.

Adding to 21213311212 its reverse (21211331212), we get a palindrome (42424642424).

The spelling of 21213311212 in words is "twenty-one billion, two hundred thirteen million, three hundred eleven thousand, two hundred twelve".