21200111001020 has 192 divisors, whose sum is σ = 54723581337600. Its totient is φ = 6742715857920.

The previous prime is 21200111001011. The next prime is 21200111001053. The reversal of 21200111001020 is 2010011100212.

It is a junction number, because it is equal to n+sod(n) for n = 21200111000992 and 21200111001010.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 16888634 + ... + 18100446.

It is an arithmetic number, because the mean of its divisors is an integer number (285018652800).

Almost surely, 2^{21200111001020} is an apocalyptic number.

21200111001020 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 21200111001020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27361790668800).

21200111001020 is an abundant number, since it is smaller than the sum of its proper divisors (33523470336580).

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

21200111001020 is a wasteful number, since it uses less digits than its factorization.

21200111001020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1212028 (or 1212026 counting only the distinct ones).

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

Adding to 21200111001020 its reverse (2010011100212), we get a palindrome (23210122101232).

The spelling of 21200111001020 in words is "twenty-one trillion, two hundred billion, one hundred eleven million, one thousand, twenty".