21300311221 has 6 divisors (see below), whose sum is σ = 24777913110. Its totient is φ = 18257409576.

The previous prime is 21300311213. The next prime is 21300311233. The reversal of 21300311221 is 12211300312.

It can be written as a sum of positive squares in only one way, i.e., 18580688721 + 2719622500 = 136311^2 + 52150^2 .

It is not a de Polignac number, because 21300311221 - 2³ = 21300311213 is a prime.

It is a super-2 number, since 2×21300311221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21300311195 and 21300311204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21300311821) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 217350066 + ... + 217350163.

It is an arithmetic number, because the mean of its divisors is an integer number (4129652185).

Almost surely, 2^21300311221 is an apocalyptic number.

It is an amenable number.

21300311221 is a deficient number, since it is larger than the sum of its proper divisors (3477601889).

21300311221 is an equidigital number, since it uses as much as digits as its factorization.

21300311221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 434700243 (or 434700236 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21300311221 its reverse (12211300312), we get a palindrome (33511611533).

The spelling of 21300311221 in words is "twenty-one billion, three hundred million, three hundred eleven thousand, two hundred twenty-one".