21300011221 has 4 divisors (see below), whose sum is σ = 21318485932. Its totient is φ = 21281536512.

The previous prime is 21300011179. The next prime is 21300011233. The reversal of 21300011221 is 12211000312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7501984996 + 13798026225 = 86614^2 + 117465^2 .

It is a cyclic number.

It is not a de Polignac number, because 21300011221 - 2⁹ = 21300010709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21300011251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9235626 + ... + 9237931.

It is an arithmetic number, because the mean of its divisors is an integer number (5329621483).

Almost surely, 2^21300011221 is an apocalyptic number.

It is an amenable number.

21300011221 is a deficient number, since it is larger than the sum of its proper divisors (18474711).

21300011221 is a wasteful number, since it uses less digits than its factorization.

21300011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18474710.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21300011221 its reverse (12211000312), we get a palindrome (33511011533).

The spelling of 21300011221 in words is "twenty-one billion, three hundred million, eleven thousand, two hundred twenty-one".