21220221211111 has 12 divisors (see below), whose sum is σ = 23159039377152. Its totient is φ = 19433661077376.

The previous prime is 21220221211097. The next prime is 21220221211117. The reversal of 21220221211111 is 11111212202212.

It is a happy number.

It is not a de Polignac number, because 21220221211111 - 2¹¹ = 21220221209063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220221211117) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 494322786 + ... + 494365711.

It is an arithmetic number, because the mean of its divisors is an integer number (1929919948096).

Almost surely, 2^{21220221211111} is an apocalyptic number.

21220221211111 is a deficient number, since it is larger than the sum of its proper divisors (1938818166041).

21220221211111 is a wasteful number, since it uses less digits than its factorization.

21220221211111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 988688650 (or 988688637 counting only the distinct ones).

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

Adding to 21220221211111 its reverse (11111212202212), we get a palindrome (32331433413323).

It can be divided in two parts, 212202212 and 11111, that multiplied together give a palindrome (2357778777532).

The spelling of 21220221211111 in words is "twenty-one trillion, two hundred twenty billion, two hundred twenty-one million, two hundred eleven thousand, one hundred eleven".