21221101010000 has 100 divisors (see below), whose sum is σ = 51383903528100. Its totient is φ = 8487532416000.

The previous prime is 21221101009993. The next prime is 21221101010027. The reversal of 21221101010000 is 1010112212.

It can be written as a sum of positive squares in 10 ways, for example, as 20968120177216 + 252980832784 = 4579096^2 + 502972^2 .

It is a tau number, because it is divible by the number of its divisors (100).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 97581386 + ... + 97798614.

It is an arithmetic number, because the mean of its divisors is an integer number (513839035281).

Almost surely, 2^{21221101010000} is an apocalyptic number.

21221101010000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21221101010000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25691951764050).

21221101010000 is an abundant number, since it is smaller than the sum of its proper divisors (30162802518100).

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

21221101010000 is an equidigital number, since it uses as much as digits as its factorization.

21221101010000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227026 (or 227005 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21221101010000 its reverse (1010112212), we get a palindrome (21222111122212).

The spelling of 21221101010000 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred one million, ten thousand".