21112021111221 has 20 divisors (see below), whose sum is σ = 31569990821292. Its totient is φ = 14060274668928.

The previous prime is 21112021111213. The next prime is 21112021111241. The reversal of 21112021111221 is 12211112021112.

It is a happy number.

21112021111221 is a `hidden beast` number, since 211 + 1 + 20 + 211 + 1 + 1 + 221 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 8250394522500 + 12861626588721 = 2872350^2 + 3586311^2 .

It is not a de Polignac number, because 21112021111221 - 2³ = 21112021111213 is a prime.

It is a super-2 number, since 2×21112021111221² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21112021111194 and 21112021111203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112021111241) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 133309930 + ... + 133468203.

Almost surely, 2^{21112021111221} is an apocalyptic number.

It is an amenable number.

21112021111221 is a deficient number, since it is larger than the sum of its proper divisors (10457969710071).

21112021111221 is an equidigital number, since it uses as much as digits as its factorization.

21112021111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266779122 (or 266779113 counting only the distinct ones).

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

Adding to 21112021111221 its reverse (12211112021112), we get a palindrome (33323133132333).

The spelling of 21112021111221 in words is "twenty-one trillion, one hundred twelve billion, twenty-one million, one hundred eleven thousand, two hundred twenty-one".