21112121022100 has 72 divisors (see below), whose sum is σ = 46844638001280. Its totient is φ = 8255175102720.

The previous prime is 21112121022089. The next prime is 21112121022149. The reversal of 21112121022100 is 122012121112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1171096 + ... + 6602704.

It is an arithmetic number, because the mean of its divisors is an integer number (650619972240).

Almost surely, 2^{21112121022100} is an apocalyptic number.

21112121022100 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 21112121022100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23422319000640).

21112121022100 is an abundant number, since it is smaller than the sum of its proper divisors (25732516979180).

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

21112121022100 is a wasteful number, since it uses less digits than its factorization.

21112121022100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5432497 (or 5432490 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21112121022100 its reverse (122012121112), we get a palindrome (21234133143212).

The spelling of 21112121022100 in words is "twenty-one trillion, one hundred twelve billion, one hundred twenty-one million, twenty-two thousand, one hundred".