21011222220102 has 96 divisors (see below), whose sum is σ = 50023473477120. Its totient is φ = 6344145244800.

The previous prime is 21011222220077. The next prime is 21011222220103. The reversal of 21011222220102 is 20102222211012.

It is a happy number.

21011222220102 is a `hidden beast` number, since 210 + 1 + 1 + 222 + 220 + 10 + 2 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011222220103) 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 47 ways as a sum of consecutive naturals, for example, 19542618 + ... + 20589714.

It is an arithmetic number, because the mean of its divisors is an integer number (521077848720).

Almost surely, 2^{21011222220102} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21011222220102, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25011736738560).

21011222220102 is an abundant number, since it is smaller than the sum of its proper divisors (29012251257018).

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

21011222220102 is a wasteful number, since it uses less digits than its factorization.

21011222220102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1049698 (or 1049695 counting only the distinct ones).

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

Adding to 21011222220102 its reverse (20102222211012), we get a palindrome (41113444431114).

The spelling of 21011222220102 in words is "twenty-one trillion, eleven billion, two hundred twenty-two million, two hundred twenty thousand, one hundred two".