21211222012 has 36 divisors (see below), whose sum is σ = 39629501856. Its totient is φ = 9928610560.

The previous prime is 21211221991. The next prime is 21211222051. The reversal of 21211222012 is 21022211212.

It is a happy number.

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 7189 + ... + 206092.

It is an arithmetic number, because the mean of its divisors is an integer number (1100819496).

Almost surely, 2^21211222012 is an apocalyptic number.

It is an amenable number.

21211222012 is a deficient number, since it is larger than the sum of its proper divisors (18418279844).

21211222012 is a wasteful number, since it uses less digits than its factorization.

21211222012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213378 (or 213353 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21211222012 its reverse (21022211212), we get a palindrome (42233433224).

The spelling of 21211222012 in words is "twenty-one billion, two hundred eleven million, two hundred twenty-two thousand, twelve".