21022121212 has 12 divisors (see below), whose sum is σ = 36796198320. Its totient is φ = 10508921696.

The previous prime is 21022121207. The next prime is 21022121251. The reversal of 21022121212 is 21212122012.

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, 512512 + ... + 552007.

It is an arithmetic number, because the mean of its divisors is an integer number (3066349860).

Almost surely, 2^21022121212 is an apocalyptic number.

It is an amenable number.

21022121212 is a deficient number, since it is larger than the sum of its proper divisors (15774077108).

21022121212 is a wasteful number, since it uses less digits than its factorization.

21022121212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1069460 (or 1069458 counting only the distinct ones).

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

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

The spelling of 21022121212 in words is "twenty-one billion, twenty-two million, one hundred twenty-one thousand, two hundred twelve".