21221211101212 has 48 divisors (see below), whose sum is σ = 37352731736320. Its totient is φ = 10549231862400.

The previous prime is 21221211101159. The next prime is 21221211101249. The reversal of 21221211101212 is 21210111212212.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21221211101212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 629300512 + ... + 629334232.

Almost surely, 2^{21221211101212} is an apocalyptic number.

It is an amenable number.

21221211101212 is a deficient number, since it is larger than the sum of its proper divisors (16131520635108).

21221211101212 is a wasteful number, since it uses less digits than its factorization.

21221211101212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35402 (or 35400 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21221211101212 its reverse (21210111212212), we get a palindrome (42431322313424).

The spelling of 21221211101212 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred eleven million, one hundred one thousand, two hundred twelve".