21200220012100 has 72 divisors (see below), whose sum is σ = 46195003596168. Its totient is φ = 8445010022400.

The previous prime is 21200220012079. The next prime is 21200220012113. The reversal of 21200220012100 is 121002200212.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 10604056576 + 21189615955524 = 102976^2 + 4603218^2 .

It is a super-2 number, since 2×21200220012100² (a number of 27 digits) contains 22 as substring.

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, 40201332 + ... + 40725268.

It is an arithmetic number, because the mean of its divisors is an integer number (641597272169).

Almost surely, 2^{21200220012100} is an apocalyptic number.

21200220012100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21200220012100 is an abundant number, since it is smaller than the sum of its proper divisors (24994783584068).

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

21200220012100 is a wasteful number, since it uses less digits than its factorization.

21200220012100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525625 (or 525618 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21200220012100 its reverse (121002200212), we get a palindrome (21321222212312).

The spelling of 21200220012100 in words is "twenty-one trillion, two hundred billion, two hundred twenty million, twelve thousand, one hundred".