21221220110202 has 144 divisors (see below), whose sum is σ = 56643690355200. Its totient is φ = 5705406878976.

The previous prime is 21221220110201. The next prime is 21221220110227. The reversal of 21221220110202 is 20201102212212.

It is a happy number.

21221220110202 is a `hidden beast` number, since 21 + 221 + 220 + 1 + 1 + 0 + 202 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21221220110201) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 76315623 + ... + 76593189.

It is an arithmetic number, because the mean of its divisors is an integer number (393358960800).

Almost surely, 2^{21221220110202} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21221220110202, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28321845177600).

21221220110202 is an abundant number, since it is smaller than the sum of its proper divisors (35422470244998).

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

21221220110202 is a wasteful number, since it uses less digits than its factorization.

21221220110202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282705 (or 282695 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21221220110202 its reverse (20201102212212), we get a palindrome (41422322322414).

The spelling of 21221220110202 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty million, one hundred ten thousand, two hundred two".