21113113221 has 12 divisors (see below), whose sum is σ = 31240542060. Its totient is φ = 13732105920.

The previous prime is 21113113201. The next prime is 21113113267. The reversal of 21113113221 is 12231131112.

21113113221 is a `hidden beast` number, since 21 + 11 + 311 + 322 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 8120532996 + 12992580225 = 90114^2 + 113985^2 .

It is not a de Polignac number, because 21113113221 - 2⁶ = 21113113157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21113113194 and 21113113203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113113201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28608186 + ... + 28608923.

It is an arithmetic number, because the mean of its divisors is an integer number (2603378505).

Almost surely, 2^21113113221 is an apocalyptic number.

It is an amenable number.

21113113221 is a deficient number, since it is larger than the sum of its proper divisors (10127428839).

21113113221 is a wasteful number, since it uses less digits than its factorization.

21113113221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57217156 (or 57217153 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

Adding to 21113113221 its reverse (12231131112), we get a palindrome (33344244333).

The spelling of 21113113221 in words is "twenty-one billion, one hundred thirteen million, one hundred thirteen thousand, two hundred twenty-one".