21210111212212 has 144 divisors (see below), whose sum is σ = 43103480367360. Its totient is φ = 9053029649664.

The previous prime is 21210111212203. The next prime is 21210111212237. The reversal of 21210111212212 is 21221211101212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a self number, because there is not a number n which added to its sum of digits gives 21210111212212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5548026133 + ... + 5548029955.

Almost surely, 2^{21210111212212} is an apocalyptic number.

It is an amenable number.

21210111212212 is an abundant number, since it is smaller than the sum of its proper divisors (21893369155148).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21210111212212 is a wasteful number, since it uses less digits than its factorization.

21210111212212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6982 (or 6937 counting only the distinct ones).

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

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

The spelling of 21210111212212 in words is "twenty-one trillion, two hundred ten billion, one hundred eleven million, two hundred twelve thousand, two hundred twelve".