21112112011221 has 96 divisors (see below), whose sum is σ = 38318437048320. Its totient is φ = 10881302140800.

The previous prime is 21112112011189. The next prime is 21112112011231. The reversal of 21112112011221 is 12211021121112.

It is a happy number.

21112112011221 is a `hidden beast` number, since 21 + 11 + 211 + 201 + 1 + 221 = 666.

It is not a de Polignac number, because 21112112011221 - 2⁵ = 21112112011189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21112112011194 and 21112112011203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112112011231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 479221431 + ... + 479265483.

It is an arithmetic number, because the mean of its divisors is an integer number (399150385920).

Almost surely, 2^{21112112011221} is an apocalyptic number.

21112112011221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21112112011221 is a deficient number, since it is larger than the sum of its proper divisors (17206325037099).

21112112011221 is a wasteful number, since it uses less digits than its factorization.

21112112011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49487 (or 49484 counting only the distinct ones).

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

Adding to 21112112011221 its reverse (12211021121112), we get a palindrome (33323133132333).

The spelling of 21112112011221 in words is "twenty-one trillion, one hundred twelve billion, one hundred twelve million, eleven thousand, two hundred twenty-one".