21021122220111 has 96 divisors (see below), whose sum is σ = 36311782066560. Its totient is φ = 11586655567872.

The previous prime is 21021122220103. The next prime is 21021122220127. The reversal of 21021122220111 is 11102222112012.

21021122220111 is a `hidden beast` number, since 21 + 0 + 211 + 222 + 201 + 11 = 666.

It is not a de Polignac number, because 21021122220111 - 2³ = 21021122220103 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021122220191) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7845895 + ... + 10178423.

It is an arithmetic number, because the mean of its divisors is an integer number (378247729860).

Almost surely, 2^{21021122220111} is an apocalyptic number.

21021122220111 is a deficient number, since it is larger than the sum of its proper divisors (15290659846449).

21021122220111 is a wasteful number, since it uses less digits than its factorization.

21021122220111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2332785 (or 2332782 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21021122220111 its reverse (11102222112012), we get a palindrome (32123344332123).

The spelling of 21021122220111 in words is "twenty-one trillion, twenty-one billion, one hundred twenty-two million, two hundred twenty thousand, one hundred eleven".