21120212211021 has 24 divisors (see below), whose sum is σ = 38034667879104. Its totient is φ = 10971538810560.

The previous prime is 21120212211001. The next prime is 21120212211061. The reversal of 21120212211021 is 12011221202112.

21120212211021 is a `hidden beast` number, since 211 + 202 + 1 + 221 + 10 + 21 = 666.

It is not a de Polignac number, because 21120212211021 - 2⁷ = 21120212210893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21120212210985 and 21120212211003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120212211001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15238247656 + ... + 15238249041.

It is an arithmetic number, because the mean of its divisors is an integer number (1584777828296).

Almost surely, 2^{21120212211021} is an apocalyptic number.

21120212211021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21120212211021 is a deficient number, since it is larger than the sum of its proper divisors (16914455668083).

21120212211021 is a wasteful number, since it uses less digits than its factorization.

21120212211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30476496721 (or 30476496718 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21120212211021 its reverse (12011221202112), we get a palindrome (33131433413133).

The spelling of 21120212211021 in words is "twenty-one trillion, one hundred twenty billion, two hundred twelve million, two hundred eleven thousand, twenty-one".