21202110011221 has 4 divisors (see below), whose sum is σ = 21653218734912. Its totient is φ = 20751001287532.

The previous prime is 21202110011183. The next prime is 21202110011321. The reversal of 21202110011221 is 12211001120212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21202110011221 - 2⁹ = 21202110010709 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21202110011195 and 21202110011204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202110011021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225554361775 + ... + 225554361868.

It is an arithmetic number, because the mean of its divisors is an integer number (5413304683728).

Almost surely, 2^{21202110011221} is an apocalyptic number.

It is an amenable number.

21202110011221 is a deficient number, since it is larger than the sum of its proper divisors (451108723691).

21202110011221 is an equidigital number, since it uses as much as digits as its factorization.

21202110011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451108723690.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21202110011221 its reverse (12211001120212), we get a palindrome (33413111131433).

The spelling of 21202110011221 in words is "twenty-one trillion, two hundred two billion, one hundred ten million, eleven thousand, two hundred twenty-one".