21220001210100 has 576 divisors, whose sum is σ = 81090989844480. Its totient is φ = 4147830374400.

The previous prime is 21220001210047. The next prime is 21220001210101. The reversal of 21220001210100 is 101210002212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220001210101) 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 191 ways as a sum of consecutive naturals, for example, 820337367 + ... + 820363233.

It is an arithmetic number, because the mean of its divisors is an integer number (140782968480).

Almost surely, 2^{21220001210100} is an apocalyptic number.

21220001210100 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 21220001210100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40545494922240).

21220001210100 is an abundant number, since it is smaller than the sum of its proper divisors (59870988634380).

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

21220001210100 is a wasteful number, since it uses less digits than its factorization.

21220001210100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28008 (or 28001 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21220001210100 its reverse (101210002212), we get a palindrome (21321211212312).

The spelling of 21220001210100 in words is "twenty-one trillion, two hundred twenty billion, one million, two hundred ten thousand, one hundred".