21200121021020 has 12 divisors (see below), whose sum is σ = 44520254144184. Its totient is φ = 8480048408400.

The previous prime is 21200121021019. The next prime is 21200121021049. The reversal of 21200121021020 is 2012012100212.

It is a super-4 number, since 4×21200121021020⁴ (a number of 54 digits) contains 4444 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21200121020986 and 21200121021004.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 530003025506 + ... + 530003025545.

It is an arithmetic number, because the mean of its divisors is an integer number (3710021178682).

Almost surely, 2^{21200121021020} is an apocalyptic number.

21200121021020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21200121021020 is an abundant number, since it is smaller than the sum of its proper divisors (23320133123164).

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

21200121021020 is a wasteful number, since it uses less digits than its factorization.

21200121021020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1060006051060 (or 1060006051058 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21200121021020 its reverse (2012012100212), we get a palindrome (23212133121232).

The spelling of 21200121021020 in words is "twenty-one trillion, two hundred billion, one hundred twenty-one million, twenty-one thousand, twenty".