21221222012 has 6 divisors (see below), whose sum is σ = 37137138528. Its totient is φ = 10610611004.

The previous prime is 21221221997. The next prime is 21221222023. The reversal of 21221222012 is 21022212212.

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 (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2652652748 + ... + 2652652755.

It is an arithmetic number, because the mean of its divisors is an integer number (6189523088).

Almost surely, 2^21221222012 is an apocalyptic number.

It is an amenable number.

21221222012 is a deficient number, since it is larger than the sum of its proper divisors (15915916516).

21221222012 is a wasteful number, since it uses less digits than its factorization.

21221222012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5305305507 (or 5305305505 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21221222012 its reverse (21022212212), we get a palindrome (42243434224).

The spelling of 21221222012 in words is "twenty-one billion, two hundred twenty-one million, two hundred twenty-two thousand, twelve".