21111202221212 has 24 divisors (see below), whose sum is σ = 38551064227200. Its totient is φ = 10096616566256.

The previous prime is 21111202221211. The next prime is 21111202221217. The reversal of 21111202221212 is 21212220211112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111202221211) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 29548739 + ... + 30254757.

It is an arithmetic number, because the mean of its divisors is an integer number (1606294342800).

Almost surely, 2^{21111202221212} is an apocalyptic number.

It is an amenable number.

21111202221212 is a deficient number, since it is larger than the sum of its proper divisors (17439862005988).

21111202221212 is a wasteful number, since it uses less digits than its factorization.

21111202221212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1031065 (or 1031063 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21111202221212 its reverse (21212220211112), we get a palindrome (42323422432324).

The spelling of 21111202221212 in words is "twenty-one trillion, one hundred eleven billion, two hundred two million, two hundred twenty-one thousand, two hundred twelve".