21211202221110 has 144 divisors (see below), whose sum is σ = 60624655116480. Its totient is φ = 5141584166400.

The previous prime is 21211202221049. The next prime is 21211202221123. The reversal of 21211202221110 is 1112220211212.

21211202221110 is a `hidden beast` number, since 21 + 211 + 202 + 221 + 1 + 10 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 112301331 + ... + 112490049.

It is an arithmetic number, because the mean of its divisors is an integer number (421004549420).

Almost surely, 2^{21211202221110} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21211202221110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30312327558240).

21211202221110 is an abundant number, since it is smaller than the sum of its proper divisors (39413452895370).

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

21211202221110 is a wasteful number, since it uses less digits than its factorization.

21211202221110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199075 (or 199061 counting only the distinct ones).

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

Adding to 21211202221110 its reverse (1112220211212), we get a palindrome (22323422432322).

The spelling of 21211202221110 in words is "twenty-one trillion, two hundred eleven billion, two hundred two million, two hundred twenty-one thousand, one hundred ten".