21021210221212 has 6 divisors (see below), whose sum is σ = 36787117887128. Its totient is φ = 10510605110604.

The previous prime is 21021210221153. The next prime is 21021210221237. The reversal of 21021210221212 is 21212201212012.

It is a self number, because there is not a number n which added to its sum of digits gives 21021210221212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2627651277648 + ... + 2627651277655.

Almost surely, 2^{21021210221212} is an apocalyptic number.

It is an amenable number.

21021210221212 is a deficient number, since it is larger than the sum of its proper divisors (15765907665916).

21021210221212 is a wasteful number, since it uses less digits than its factorization.

21021210221212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5255302555307 (or 5255302555305 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21021210221212 its reverse (21212201212012), we get a palindrome (42233411433224).

The spelling of 21021210221212 in words is "twenty-one trillion, twenty-one billion, two hundred ten million, two hundred twenty-one thousand, two hundred twelve".