21112211121021 has 48 divisors (see below), whose sum is σ = 32294315342016. Its totient is φ = 13778069175936.

The previous prime is 21112211120929. The next prime is 21112211121031. The reversal of 21112211121021 is 12012111221112.

It is a happy number.

21112211121021 is a `hidden beast` number, since 211 + 1 + 221 + 1 + 1 + 210 + 21 = 666.

It is not a de Polignac number, because 21112211121021 - 2¹⁹ = 21112210596733 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21112211120985 and 21112211121003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112211121031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3855201 + ... + 7555593.

It is an arithmetic number, because the mean of its divisors is an integer number (672798236292).

Almost surely, 2^{21112211121021} is an apocalyptic number.

It is an amenable number.

21112211121021 is a deficient number, since it is larger than the sum of its proper divisors (11182104220995).

21112211121021 is an equidigital number, since it uses as much as digits as its factorization.

21112211121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3700904 (or 3700892 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21112211121021 its reverse (12012111221112), we get a palindrome (33124322342133).

The spelling of 21112211121021 in words is "twenty-one trillion, one hundred twelve billion, two hundred eleven million, one hundred twenty-one thousand, twenty-one".