21101221010100 has 576 divisors, whose sum is σ = 77049768499200. Its totient is φ = 4331086848000.

The previous prime is 21101221010099. The next prime is 21101221010173. The reversal of 21101221010100 is 101012210112.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 2321106555 + ... + 2321115645.

It is an arithmetic number, because the mean of its divisors is an integer number (133766959200).

Almost surely, 2^{21101221010100} is an apocalyptic number.

21101221010100 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 21101221010100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38524884249600).

21101221010100 is an abundant number, since it is smaller than the sum of its proper divisors (55948547489100).

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

21101221010100 is a wasteful number, since it uses less digits than its factorization.

21101221010100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10344 (or 10337 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21101221010100 its reverse (101012210112), we get a palindrome (21202233220212).

The spelling of 21101221010100 in words is "twenty-one trillion, one hundred one billion, two hundred twenty-one million, ten thousand, one hundred".