21103330221 has 10 divisors (see below), whose sum is σ = 31524727982. Its totient is φ = 14068886760.

The previous prime is 21103330219. The next prime is 21103330223. The reversal of 21103330221 is 12203330112.

21103330221 is a `hidden beast` number, since 2 + 110 + 3 + 330 + 221 = 666.

It is an interprime number because it is at equal distance from previous prime (21103330219) and next prime (21103330223).

It can be written as a sum of positive squares in only one way, i.e., 15325202025 + 5778128196 = 123795^2 + 76014^2 .

It is not a de Polignac number, because 21103330221 - 2¹ = 21103330219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21103330194 and 21103330203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21103330223) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 130267390 + ... + 130267551.

Almost surely, 2^21103330221 is an apocalyptic number.

It is an amenable number.

21103330221 is a deficient number, since it is larger than the sum of its proper divisors (10421397761).

21103330221 is an equidigital number, since it uses as much as digits as its factorization.

21103330221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 260534953 (or 260534944 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21103330221 its reverse (12203330112), we get a palindrome (33306660333).

The spelling of 21103330221 in words is "twenty-one billion, one hundred three million, three hundred thirty thousand, two hundred twenty-one".