21210110011221 has 8 divisors (see below), whose sum is σ = 28280170792224. Its totient is φ = 14140061285520.

The previous prime is 21210110011199. The next prime is 21210110011253. The reversal of 21210110011221 is 12211001101212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21210110011221 - 2¹⁰ = 21210110010197 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21210110011221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210110011421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2568631 + ... + 7001291.

It is an arithmetic number, because the mean of its divisors is an integer number (3535021349028).

Almost surely, 2^{21210110011221} is an apocalyptic number.

It is an amenable number.

21210110011221 is a deficient number, since it is larger than the sum of its proper divisors (7070060781003).

21210110011221 is a wasteful number, since it uses less digits than its factorization.

21210110011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6027651.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21210110011221 its reverse (12211001101212), we get a palindrome (33421111112433).

The spelling of 21210110011221 in words is "twenty-one trillion, two hundred ten billion, one hundred ten million, eleven thousand, two hundred twenty-one".