21212122012 has 12 divisors (see below), whose sum is σ = 37675261960. Its totient is φ = 10447761456.

The previous prime is 21212121971. The next prime is 21212122027. The reversal of 21212122012 is 21022121212.

It is a happy number.

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, 39574587 + ... + 39575122.

Almost surely, 2^21212122012 is an apocalyptic number.

It is an amenable number.

21212122012 is a deficient number, since it is larger than the sum of its proper divisors (16463139948).

21212122012 is a wasteful number, since it uses less digits than its factorization.

21212122012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79149780 (or 79149778 counting only the distinct ones).

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

Adding to 21212122012 its reverse (21022121212), we get a palindrome (42234243224).

The spelling of 21212122012 in words is "twenty-one billion, two hundred twelve million, one hundred twenty-two thousand, twelve".