21200111022121 has 8 divisors (see below), whose sum is σ = 21604260089160. Its totient is φ = 20796115546752.

The previous prime is 21200111022091. The next prime is 21200111022203. The reversal of 21200111022121 is 12122011100212.

It can be written as a sum of positive squares in 4 ways, for example, as 15891671982096 + 5308439040025 = 3986436^2 + 2304005^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21200111022121 - 2¹⁷ = 21200110891049 is a prime.

It is a super-2 number, since 2×21200111022121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21200111022095 and 21200111022104.

It is not an unprimeable number, because it can be changed into a prime (21200111022421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38119210 + ... + 38671363.

It is an arithmetic number, because the mean of its divisors is an integer number (2700532511145).

Almost surely, 2^{21200111022121} is an apocalyptic number.

It is an amenable number.

21200111022121 is a deficient number, since it is larger than the sum of its proper divisors (404149067039).

21200111022121 is an equidigital number, since it uses as much as digits as its factorization.

21200111022121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76795835.

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

Adding to 21200111022121 its reverse (12122011100212), we get a palindrome (33322122122333).

The spelling of 21200111022121 in words is "twenty-one trillion, two hundred billion, one hundred eleven million, twenty-two thousand, one hundred twenty-one".