21200020022100 has 144 divisors (see below), whose sum is σ = 64956636134208. Its totient is φ = 5319990466560.

The previous prime is 21200020022099. The next prime is 21200020022131. The reversal of 21200020022100 is 122002000212.

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 47 ways as a sum of consecutive naturals, for example, 34029607 + ... + 34646993.

It is an arithmetic number, because the mean of its divisors is an integer number (451087750932).

Almost surely, 2^{21200020022100} is an apocalyptic number.

21200020022100 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 21200020022100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32478318067104).

21200020022100 is an abundant number, since it is smaller than the sum of its proper divisors (43756616112108).

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

21200020022100 is a wasteful number, since it uses less digits than its factorization.

21200020022100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624154 (or 624147 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 21200020022100 its reverse (122002000212), we get a palindrome (21322022022312).

The spelling of 21200020022100 in words is "twenty-one trillion, two hundred billion, twenty million, twenty-two thousand, one hundred".